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Waivers available for articles submitted in 2024, npj Sustainable Agriculture has waivers available to offer that can be allocated upon acceptance on an ad-hoc basis. For additional information contact the Managing Editor .

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• Published: 12 September 2024

Overview and recommendations for research on plants and microbes in regolith-based agriculture

• Laura E. Fackrell 1 ,
• Samson Humphrey 2 ,
• Rafael Loureiro 3 ,
• Andrew G. Palmer 4 , 5 &
• Jared Long-Fox 6  

npj Sustainable Agriculture volume  2 , Article number:  15 ( 2024 ) Cite this article

Metrics details

• Microbial communities
• Element cycles
• Environmental microbiology
• Plant development
• Plant physiology
• Plant stress responses

The domestication of agriculture is widely recognized as one of the most crucial technological adaptations for the transition of humanity from hunter-and-gatherer groups into early city-states and ultimately, complex civilizations. As humankind sets forth to permanently establish itself on the Moon and use it as a testing ground to colonize other worlds, like Mars, agriculture will again play a pivotal role. In this case, the development of sustainable crop production systems capable of succeeding in these harsh environments becomes vital to the success of our star-faring journey. Over decades, studies varying in species and approaches have been conducted in microgravity, testing the limits of plants and various growth systems, to better understand how Earth-based agriculture could be translated into environmental conditions and therefore evolutionary pressures beyond what life on our planet has known. While we have passed several significant milestones, we are still far from the goal of a sustainable agricultural system beyond our planet Regolith-based agriculture (RBA) should be a component of sustainable agriculture solutions beyond Earth, one which can also provide insight into plant growth in poor soils across our own world. However, RBA studies are in their infancy and, like any other new field, need an established set of parameters to be followed by the RBA community so the generated data can be standardized and validated. Here, we provide an extensive multi-disciplinary review of the state of RBA, outline important knowledge gaps, and propose a set of standardized methods and benchmarks for regolith simulant development and selection as well as plant, microbe, and plant-microbe interaction studies conducted in lunar and Martian regolith. Our goal is to spur dialog within the RBA community on proper regolith simulant selection, experimental design, and reporting. Our methods are divided into complexity tiers, providing a clear path for even the simplest experiments to contribute to the bulk of the knowledge that will shape the future of RBA science and see it mature as an integrated part of sustainable off-world agriculture.

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Introduction.

Crewed space missions depend upon the control and integration of a tremendous number of systems and features simultaneously, with the ultimate goal of establishing a sustainable artificial ecosystem despite being surrounded by an environment ill-suited for human life. Among the numerous mission-critical components which need to be considered in the development of this artificial ecosystem, consistent access to a safe, sustainable, and sufficiently nutritious food supply is one of the highest priorities 1 . Absolute dependence on resupply missions from Earth is expensive, risky, and would continue to deplete resources from our own planet, all factors which would ultimately jeopardize any established colony. With estimates that continuous off-world settlements will be a reality within 50 years, temporary habitats will be established far sooner, and a reliable supply of nutrition will be crucial to support these missions.

The development of bioregenerative food systems (BFS) have been proposed as the most cost-effective approach for reducing the frequency of resupply missions and are crucial to enabling sustainable planetary colonization 2 , 3 , 4 , 5 , 6 , 7 , 8 . Current food production systems can supplement present day missions within low Earth orbit (LEO) but are neither sustainable nor up to the task of supporting the future demands of deep space exploration 3 , 6 . Existing BFS such as Veggie growth chamber and the APH (Advanced Plant Habitat) employ hydroponic strategies that have proven effective in the microgravity environment of the International Space Station (ISS) 9 . However, different solutions will be required to support long-term surface settlements off-world.

Unlike the ISS, lunar and planetary settlement efforts can utilize additional in situ (i.e., on-site) resources (ISR) available including water, atmospheric components (e.g., O 2 and/or CO 2 ), and most notably, the regolith that comprises their surfaces. In situ resource utilization (ISRU) of regolith as a substrate for plant growth has been widely regarded as potentially valuable for food production as regolith is a physical substrate and a potential source of plant nutrients (Iron, Potassium, Magnesium, etc.). This substrate does not need to be shipped from Earth reducing total costs and labor. Moreover, regolith-based agriculture (RBA) leverages centuries of agricultural knowledge and the evolutionarily adapted relationship between plants, microorganisms, and soil to support plant growth and food production. RBA can incorporate sustainable agricultural approaches that we use on Earth to minimize fertilizer consumption, avoid the spread of pathogens, promote nutrient cycling, and support interactions with beneficial microorganisms 10 . Furthermore, RBA can operate in parallel with other agricultural approaches (e.g., hydroponics, soilless substrates, etc.), enabling us to design a more diverse, secure, and sustainable approach for off-world food production, instead of a one-size-fits-all system.

However, despite the potential of RBA to serve as a major component in lunar and planetary-based food systems, efforts to develop and evaluate the viability of this approach have faced a number of challenges. Chief among these is the fact that little or no supply of actual lunar or Martian regolith is available for this research, forcing a reliance upon terrestrially or anthropogenically sourced proxies (termed regolith simulant ’). This alone has created considerable variability in conclusions made about the viability of RBA. Additionally, studies vary widely in approach, growing conditions, plant selection, metrics for success, etc. This is not unexpected as emerging research areas, like all new frontiers, are fueled by innovation and marked by rapid, often unrestrained growth. Therefore, as the number of researchers and projects associated with any field continues to grow, it becomes necessary to establish specific conventions and best practices.

We stand at this point in the regolith community, where a critical mass of researchers has developed, and our capacity to successfully evaluate the true in situ resource potential of the lunar and Martian surface depends on establishing common protocols and terminology to effectively communicate and more objectively evaluate our work collectively. Herein we provide an extensive review of Martian and lunar regolith simulants applied to agricultural research in support of future off-world colonies. Drawing from this substantial, yet disparate, body of work we propose a ranked set of “best practices” for RBA research.

Our goals are to: (i) to inform researchers at multiple institutional levels and from various fields of expertise, (ii) to improve efforts to compare and communicate results of RBA research including increased collaboration and consultation, (iii) identify critical knowledge gaps in RBA research, (iv) and ultimately provide a more accurate assessment of the viability and technology readiness level (TRL) of RBA as a component of food-systems and bioregenerative-life support for off-world colonization. The writing of this document has been a collaborative exercise, one which has inspired new projects between the authors. In this spirit, we hope the readers will be similarly inspired to seek out collaborative approaches to best leverage expertise and produce the deliverables necessary to support sustainable food production on lunar or Martian colonies.

Properties and challenges of regolith as a growth substrate

The Moon and Mars have always been a subject of human fascination providing a wealth of data obtained through remote sensing and robot missions 11 , 12 and returned or soon to be returned samples for terrestrial-based analysis 13 , 14 . The regoliths of both surfaces could potentially provide multiple agriculturally relevant resources. For example, Mars provides access to carbonate and acidic sulfate materials potentially useful in the regulation of pH of nutrient fluids applied to agricultural systems. The Moon similarly provides potentially useful substrates and additionally serves as a testing ground for the first suite of off-world agricultural systems used to develop similar systems for Mars.

However, lunar and Martian regolith are also very different: The lunar regolith is created through space weathering (impact processes, radiation, no atmosphere) over billions of years in a reducing, vacuum environment 15 , 16 . while Martian regolith results from various impact, eolian, aqueous and other processes acting over billions of years on a globally basaltic crust 12 , 17 . This has produced two very different regolith substrates that present unique challenges for agriculture.

Analysis of the overall chemical makeup represented as elemental oxides alone is insufficient to fully describe or predict regolith viability (i.e., fertility). In evaluating the viability of soil, soilless media, or regolith as a growing medium, a variety of characteristics are considered including nutrient content and mobility, pH, salinity, contaminants/toxins, organic content, texture, density, porosity, strength (shear and compressive), etc. Thus, to understand the potential of Martian or lunar regolith as a growth medium (and appropriately mimic it) a variety of characteristics that more fully describe (or mimic) this should be applied. Here we provide an overall summary of lunar and Martian regolith-fertility as currently understood. This includes a summary of the overall chemistry, mineralogy, and physical characteristics (texture, soil strength, etc.), a comparison of overall elemental abundance to plant requirements (Table 1 ), and how well constrained/understood these aspects are currently and what relevance these hold to the application of regolith as a growing medium.

Defining regolith

To address the challenges facing RBA for successful implementation, it is essential to accurately simulate relevant characteristics of the target regolith. Indeed, even the term “regolith“ can introduce confusion into the discussion depending on the definition applied and the common practice of interchangeably using terms such as “regolith“ and “soil”, or even referring to non-regolith materials (e.g., bed-rock deposits) as regolith. Regolith is defined as the “unconsolidated material covering bedrock and can include dust, broken up rocks, soil and other related materials” 18 , 19 , 20 . Thus, regolith incorporates a variety of unconsolidated materials on the surface separating it from consolidated units that would be termed bedrock. However, weathering produces a gradation from un-weathered bedrock to fully developed soils and it can be difficult to pinpoint the exact point at which the material is unconsolidated enough to be considered regolith and no longer bedrock.

As regolith encompasses a broad range of materials, it is useful to distinguish different fractions of the regolith using terms such as soil and dust, depending on the particular context. For example, when examining the pedological history of the regolith, distinguishing among dust, soil, etc. is practical as different processes (i.e., eolian-wind and fluvial-river) affect these portions differently. Such variations provide important distinctions in interpreting the resulting history recorded in the materials. Similarly, from an engineering perspective “soil” and “dust” represent behaviorally and physically separable portions of the regolith 21 , 22 . For these and other examples, it is useful and appropriate to refer to a particular portion of the regolith as soil.

However, this “soil-like” portion of lunar and Martian regolith is distinctly “unsoil-like” from an agricultural perspective, in particular in its lack of well-developed soil horizons, absence of organic matter, and other characteristics more typical of common “agricultural soils”, making the term “soil” less useful in an agricultural context. Soil is a complex matrix, and details of its components can be found in Table S1 . Due to the distinct agriculturally relevant differences between agricultural earth soils and extra-terrestrial “soils”, it is useful to use the term regolith when speaking of extra-terrestrial “soils” as an agricultural material. Thus, this work will use the term regolith to refer to the unconsolidated “soil-like” materials or in other words material one could readily scoop off the surface, not necessarily including or excluding dust (SI Section Table S1 ). The term bedrock or other appropriate terms are used for non-regolith materials, and the term surface materials refers to any surface/near surface material: both regolith and non-regolith.

Lunar regolith characteristics

Lunar regolith composition and chemistry.

The lunar surface can be divided into two main, distinct geologic provinces: the felsic lunar highlands and the mafic lunar mare 23 . The lunar highlands are dominantly anorthositic 11 , 24 with up to 98% anorthite content 25 . The lunar highlands regolith (e.g., Apollo 16 and Luna 20) is dominantly felsic, composed of calcium-rich plagioclase with little pyroxene and other mafic, magnesium- and iron-rich mineral content 13 , 15 , 24 . It is assumed that the mixing of basaltic materials with the felsic highlands material is due to impact gardening and ejecta being distributed around the surface of the Moon due to the low gravity and high energy nature of impacts. The lunar mare is thought to have formed from basaltic volcanic materials rising from the lunar mantle after the initial formation of the Moon 26 . The mineralogy of the lunar mare regolith (e.g., Apollo 11, 12 and Luna 16, 24) is nominally basaltic, containing mostly ferromagnesian minerals with clinopyroxenes, olivine, ilmenite, and lesser amounts of calcium-rich plagioclase relative to the highlands 24 , 27 , 28 . Though the composition of regolith in the lunar mare is generally consistent from site to site, the youngest regions have unusually high concentrations of potassium (K), rare earth elements (REE), and phosphorus (P); these regions are called the Procellarum KREEP Terrane 29 . Apollo 15 and 17 landings were made in areas marginal to highlands and mare and have compositions intermediate to both with rock fragments derived from both provinces 13 , 15 . Phosphorus is found in relatively minor, but consistent, amounts in the lunar regolith 30 and particularly in the KREEP terranes in minerals such as schreibersite 31 . Potassium is an incompatible trace element in the lunar regolith 30 , and the potassium content of the lunar regolith is mostly found in the KREEP regolith. The lunar regolith has a negligible nitrogen content, and the nitrogen that is present was mostly deposited by solar winds 30 . This makes lunar KREEP materials potential sources of nutrients for plant growth (Table 1 ).

The lunar surface is significantly altered by space weathering, creating nanophase iron particles and glassy agglutinates in its regolith due to the Moon’s lack of atmosphere and vacuum conditions 15 , 32 ; Most lunar agglutinates are enriched in iron, magnesium, titanium, manganese, chromium, and scandium and other lithophile elements such as potassium, lanthanum, and cerium, but are depleted in elements compatible with plagioclase relative to bulk regolith regardless of formation in mare or highlands regions 33 , but the lunar mare is noted to have a higher agglutinate content than the highlands. The abundance of agglutinates and the ratio of nanophase iron concentration to the total iron content of lunar regolith is the maturity index of the regolith 32 , 34 in the lunar regolith and is a function of the duration of surface exposure 35 , 36 . The enrichment in ferromagnesian and lithophile elements is more pronounced in immature regolith and as regolith maturity increases, an increased proportion of plagioclase is observed in agglutinitic materials 33 , 34 . This maturity affects the regolith’s composition, especially in finer fractions, where the resemblance to agglutinate glasses increases and presence of nanophase iron increases, highlighting the dynamic nature of the lunar surface composition.

The composition described provides a medium rich in calcium, aluminum, magnesium, iron, and titanium but with much smaller amounts of nitrogen, phosphorus, potassium and sodium 30 , 37 . The high calcium, aluminum, magnesium, iron, and titanium content of the lunar regolith is potentially useful for plant growth, as these elements play roles in nutrient supply, growth, growth stimulation, and photosynthesis. However, these elements are not guaranteed to be bioavailable to plants and may require additional effort to mobilize these elements for use. The lack of nitrogen, phosphorus, and potassium also represents a significant challenge as these are major elements required for plant growth. This means that the lunar regolith will need to be processed and amended to increase mobility of certain nutrients and incorporate missing nutrients to enable optimal plant growth (see Table 1 ). What exactly these processing needs entail and what nutrients this will affect them is an area of needed research.

Lunar regolith physical properties and implications for plant growth

The particle size distribution and specific surface area of a medium for plant growth influence the permeability and fluid retention properties of the material 38 , and thus directly impact plant growth. Particle size analysis of lunar regolith shows that the mean grain size of returned samples ranges from 40 µm to 800 µm, with a lunar global average between 60 and 80 µm 15 , 39 . The wide range of particle sizes in lunar regolith allows for smaller particles to nest between larger ones, causing more complete filling of void space and decreasing permeability. Since the lunar regolith and appropriate simulants are composed of igneous mineral grains, water retention is controlled by the bulk porosity and the pore content of individual grains (measured by specific surface area), which is low compared to soils and other carbon-rich materials 38 . These properties of the lunar regolith imply that there are particle sizes and particle size distributions that give the required porosity and permeability for plant growth in lunar regolith that must be carefully balanced in regolith-soil mixes to allow for the most efficient delivery of water and nutrients.

In order to seek out local resources (e.g., water and other nutrients), plant roots grow and push their way through the growing medium. The compressive and shear strength of a plant growing medium determines the relative ease of penetration; a stronger material is harder for roots to push through. The shear and compressive strength of a material increases with increasing relative density and decreasing porosity. The density and porosity of lunar regolith have been shown to vary from site to site on the Moon and increase with depth within a single site, implying that mechanical strength varies in the same manner 40 . From a low relative density, the lunar regolith compresses significantly due to the high initial porosity and the crushing of weak, glassy grains during compression, but a minor change in initial relative density during compression leads to differing compressive strength estimates, especially in the relatively less dense upper 30 meters of regolith 40 . These results have strong implications for acceptable densities and amounts of compression of lunar regolith mixes for plant growth in terms of both root penetration and permeability for water delivery. Lunar regolith has high cohesive and frictional strength 40 , 41 making penetration (whether instrumentation or plant roots) difficult, and increasing the required amount of energy a plant must expend to reach nutrients as the root system expands.

Martian regolith characteristics

Martian regolith composition and chemistry.

The Martian regolith has a generally basaltic mineralogical profile that thus far has been globally homogenous (though there are locally altered soils that deviate from this) 12 , 42 , 43 , 44 , 45 , 46 , 47 The mineralogical profile of the regolith includes plagioclase, pyroxenes and olivine as major phases and magnetite, ilmenite, quartz, potassium feldspars and various salts as minor phases 48 , 49 , 50 , 51 . Two specific sites with samples taken by Curiosity from which this data is available include Rocknest and Gobabeb, both basaltic sands sampled within Gale Crater 49 .

In addition to identified mineral phases, all of Mars surface materials so far examined using XRD have included what has been termed an amorphous fraction consisting of crystallographically disordered materials that make-up ~20 to 50% of the sample 52 , 53 . The exact compositional make-up of this amorphous fraction is poorly constrained and variable among different surface materials, but a general chemical make-up of a particular sample can be understood with the application of multiple instruments and techniques 54 . It is thought to include materials like basaltic glass, nanophase iron oxides (e.g., ferrihydrite and maghemite), proto-phyllosilicates, carbonate and sulfate and other highly disordered materials (e.g., allophane or hesingerite) 48 , 54 , 55 , 56 , 57 , 58 , 59 . Such disordered phases are often the most reactive in Earth soils and can greatly influence overall soil fertility 60 . Thus, although poorly constrained, to the greatest extent possible it is important to appropriately represent these phases in regolith-based agricultural experiments 19 , 61 , 62 .

The compositional profile from both crystalline and non-crystalline phases provides an abundance of P, Mg, Ca, Fe, Na, Cl and Si moderate amounts of K and only trace amounts of N, relative to plant’s needs. Of course, this does not take into account the bioavailability of these nutrients but many of the minerals these are found in tend to be more bioavailable forms so at least some portion is expected to be plant extractable. Another important caveat is that some micronutrients (in particular Fe, Na, Cl, or Mg) may be present at phytotoxic levels. However, it must be noted that the amount of any micronutrient required to cause phytotoxicity varies depending on the plant species, substrate pH, and other synergistic or antagonistic nutrients present in the substrate. Additionally, though the overall chemistry and mineral profile (outside of the amorphous fraction) is fairly well understood for present day Mars soil 42 , 61 , 63 , other characteristics are less well-constrained or can only be inferred from indirect analysis based on available data. This includes features such as pH, salinity (including the implications of perchlorates/chlorates), nutrient content and mobility. All the major macronutrients and most required by plants have been detected in Mars regolith or meteorites 63 , 64 and the mobility and bioavailability of these can be inferred to some extent but is generally not well understood.

The Mars Phoenix Lander mission provides the only direct measurements of pH and salinity to present-day Mars soil providing one location and three samples of direct measurement 65 , 66 , 67 , though pH and other geochemical aspects can be somewhat inferred from other mission such as the Viking Landers. More recent analysis of soils at Gale crater provide enough information that we can indirectly infer that the overall characteristics are likely to carry over, though there is variation in the ratio of salts found 68 . The pH of Mars soil measured by Phoenix Lander averaged ~7.7 ± 0.3 indicating an alkaline soil 67 , 69 . It should be noted that this pH is within the acceptable range for most crop plants (~5 to ~8), and that at this pH most nutrients are bioavailable for plant uptake. Data from multiple missions (including Phoenix and Curiosity) provide an estimate of about 1–3 wt% salts in the regolith dominated by various Mg, Ca, and Na perchlorate, sulfate and carbonates 65 , 67 , 70 , 71 , 72 , though some regolith and bedrock salt concentrations can be much higher 73 . The ratio does vary (there is a higher proportion of perchlorates from Phoenix Lander samples than from Gale crater samples) though Mg and Ca tend to be much more dominant over Na salts 67 , 71 , 72 .

The presence of so much salt in the regolith makes salinity one of the major concerns for Martian regolith in growing plants (among other important potential applications). Preliminary regolith experiments that used high concentrations of perchlorates (2 wt%) resulted in no plant germination, where other experiments with lower concentrations resulted in plants with a significantly lower dry biomass and smaller leaf area overall 10 , 74 . Visscher et al. demonstrated severely limited growth of Arabidopsis thaliana in response to Mars-like levels of magnesium sulfate 73 . Thus, the overall salinity is high enough to be problematic for salt sensitive crops, but the most prominent concern is the perchlorate, as it can also induce molecular oxidative stress 75 . Perchlorates likely occur at high enough concentrations to create concerns for toxicity of food sources (however this depends on the extent that it is taken up into the edible organs, which depends on the crop), though a more precise understanding of the potential for bioaccumulation has not been established 76 , 77 .

Martian regolith physical properties and implications for plant growth

Much like the lunar regolith, Martian regolith has been subjected to a long history of impact processes which influence particle size frequency and other grain characteristics. Eolian and fluvial processes additionally sort and alter grain characteristics and the balance of these are key in the resulting grain characteristics and thus the resulting cohesive and shear strength of the regolith. For present day regolith eolian and impact processes are the dominant processes of concern 78 . Impact processes tend to have poorly sorted, angular materials which can increase cohesion while eolian processes tend to increase sorting and rounding of grains, decreasing cohesion. Particle size frequencies also differ: eolian ripples are often bimodal (occasionally multimodal) likely indicating the involvement of multiple processes 79 . Herkenhoff et al. measured bedforms in Gusev crater to have one mode dominated by grains between 1 and 2 mm and the other dominated by grains below 210 µm 79 . Outside the bedforms, a mixture of grain sizes and clasts was observed.

Thus, the cohesive and shear strength of Mars regolith resulting from grain characteristics can vary depending on which processes dominate. This is seen in recent challenges of “drilling” into the surface faced by the InSight mission “mole” probe designed to function in a cohesionless material (such as a basaltic sand) but failed to penetrate to adequate depth due in part to the higher than expected cohesion 80 . Like lunar regolith, these physical properties of the regolith limit the ability of root penetration and development making plant development difficult in the regolith without appropriate treatment.

In addition to the physical and mechanism contributions contributed by particle size, density, and angularity to the cohesion and shear strength of Martian regolith, the aggregational nature of certain materials in Mars regolith, namely salts, increase the regolith’s cohesive aspects 78 . The precipitation of salts in the regolith help to cement the soils together and the occurrence of cemented chunks or even duricrusts has been observed during the course of multiple missions including InSight and Curiosity 51 , 81 , 82 . Because this cement is at least partially soluble in water, any treatments or processing with water (including watering plants) can also affect the distribution or extent of cementation within a sample, perhaps decreasing it with rinsing. Thus, appropriate processing of Martian regolith must take these both the physical and chemical (cementing) aspects into account when considering effective approaches to addressing the regolith strength for agricultural applications.

Overview and current state of the challenges of lunar and Martian regolith as a growing medium

The above discussion presents both benefits and limitations for using regolith on the Moon and Mars for growing plants. The challenge for current and future research is to present ways in which limitations may be ameliorated, benefits maximized, and the overall result compared with other avenues to determine the most sustainable agricultural approaches to apply.

Since the Moon is Earth’s nearest cosmologic neighbor, human infrastructure that is developed on the lunar surface will benefit from the comparatively easy and quick access to terrestrial resources, even though established lunar colonies are intended to be mostly self-sustaining. This means that it is more feasible to supplement the lunar regolith with fertilizers from Earth or from waste and recycling if there are vital nutrient deficiencies that cannot be addressed using in situ lunar materials. This convenience is exclusive to the Moon because of the small distance to Earth, so other planetary settlements (e.g., Mars) will need to be able to supply the necessary nutrients with little to no material input from Earth.

In general, those nutrients required to supply fertilizer could be provided from in situ or waste materials efficiently recycled. Macronutrients such as nitrogen, phosphorus and potassium are of particular concern as they would be required at volumes that would be difficult to supply from Earth 64 . Phosphorus is relatively abundant on Mars and at least some fraction in plant extractable form 83 . Potassium is not particularly high in the Martian soil, but is present in bedrock units and could potentially be obtained from other surface materials in situ 84 . However, Potassium and Phosphorus are limited on the Moon and would likely need to be supplemented from Earth-based sources, or provided by plants and people pseudo-in situ 85 . Nitrogen has been detected on both the Moon and Mars, but only in trace amounts and no reserves large enough to support in situ supplies has been detected 68 , 86 . Micronutrients like iron, boron, and chloride are frequently detected on Mars and likely available in situ, but may also be problematic if present at too high of concentration of a bioavailable form to become toxic 87 . The Moon contains an abundance of metallic nanophase iron that depending on mobility may have concerns for iron toxicity as well, though studies are needed to establish the expectant mobility within closed systems presented by lunar colony habitats. Calcium, magnesium, and sulfur are very abundant on Mars and expected to be plant extractable through salts. Salts present a problem in and of themselves 66 , 67 , 88 , but even the issues of salinity on Mars have potential solutions 73 .

One potential solution is to genetically modify crop plants to tolerate higher concentrations of perchlorates, which has been somewhat effective in Arabidopsis 73 , however this has only been demonstrated in Arabidopsis, and will likely not be developed in larger crops within a reasonable timeframe, if at all. Another commonly cited solution is rinsing of the regolith as each of the problematic salts are readily soluble and could potentially be rinsed out of the soil. However, initial experiments from Oze et al. demonstrate limitations to this approach 74 . Perchlorate may also play a role as a resource as various biogenic reactions can degrade perchlorate to chloride producing oxygen as abyproduct 77 . However, even though potentially useful, there are many aspects of such an approach that need to be addressed: e.g., to what extent biogenic reactions would be effective, how much oxygen could be expected, and what to do with the chloride that results which is also problematic at those concentrations for the plants.

Lunar and Martian regolith simulants and agriculture research

In order to identify appropriate methods for processing regolith for agricultural applications, potential methods must be tested. However, samples of regolith are not generally available for use in agricultural research. Instead, regolith simulants are created that attempt to mimic the characteristics of actual regolith. In order for results to accurately reflect plant response to regolith-based growing mediums, they must accurately mimic agriculturally relevant characteristics of actual regolith 19 , 22 , 61 , 89 , 90 , 91 . Multiple regolith simulants have been produced for both the Moon and Mars and a summary of these is available from a recent review by ref. 22 .

The accuracy of a regolith simulant is limited by many factors including the availability of data for the target regolith, materials that resemble the target regolith, and feasibility of mimicking particular characteristics on a large scale 91 . For example, lunar regolith contains agglutinates and nanophase iron that are likely to have significant effects for agriculture, but very few simulants mimic these characteristics due to the difficulty of reproducing them on even a small scale. Martian regolith contains salts and other components relevant to agriculture identified in recent missions such as Curiosity. However, the most widely used Martian regolith simulants (JSC Mars 1a and Mars Mojave Simulant (MMS-1 and MMS-2)) do not contain these components as they were developed early in the exploration of Mars before such characteristics were well understood 19 , 61 , 89 , 92 . As data and methods improve, so does the need to create new simulants that more accurately mimic the target regolith. Indeed, the last few years have seen great efforts in increasing the accuracy of both lunar and Martian simulants including a few higher-quality commercially available options 19 , 61 , 93 , 94 . However, it is not feasible to mimic every aspect of regolith so even the more accurate simulants are often more accurate in features particular to a specific application. The review provided above and best practices recommended below do not intend to sponsor or promote any particular simulant. Rather we emphasize the need to ensure the accuracy of relevant characteristics for simulants aspects applied to RBA research to the extent possible and relevant for addressing the fundamental questions intended in the study.

A brief history of regolith-based agriculture research

Over decades, researchers have theorized about growing crops on the Moon and Mars.

As early as 1970, Walkinshaw and his collaborators analyzed plant physiology and productivity when exposed to lunar materials from the Apollo missions 95 , 96 , 97 .

Baur et al. and Milov and Rusakova, built on these preliminary studies, with the latter adapting a more applied view by suggesting a closed greenhouse system as a possible solution 98 , 99 .

The closed greenhouse idea would be later explored by Walkinshaw in 1986 while he tried to fully understand the interaction between plants, regolith, and microorganisms in an enclosed system 100 .

Mashinskiy and Nechitaylo’s “The Birth of Space Agriculture” was the first organized review on the subject 101 .

Ming and Henninger published a book that directly addressed this subject in a compilation of articles that discussed the feasibility of off-world Agriculture 102 . In this book, Fairchild and Roberts 103 contemplated options for human settlement on the Moon and Mars in a detailed way and divided their narrative into four scenarios entitled “The 1988 Case Studies” 102 . The first scenario was a human expedition to Phobos that did not involve ISRU utilization. The second was a human expedition to Mars with a crew of eight, where four crew members would reach the surface to collect data with heavy orbital support and some IRSU utilization. The third case study was a lunar observatory outpost that would switch categories and be classified as a science outpost in the resource allocation category. The outpost would house a crew of 4 for 20 days while all the resources would be provided in situ to the crew during this period but still with partial orbital support. The fourth and last case, the Lunar Outpost to Early Mars Evolution scenario, would be an ISRU-based, self-sustaining station housing a crew of eight over a period from 24 to 52 weeks between rotations 103 . The concerns and possible solutions to the technical, economic, political, and cultural issues that acted as barriers to permanent settlement beyond LEO in their time remain relevant to this day.

However, case studies like those listed above-inspired researchers to overcome these challenges and ultimately provided the foundational data to begin the discussion of ISRU for life support systems and led to the creation of NASA’s Controlled Ecological Life Support System program. Ripples of this movement were fast to follow, with publications focused on integrating ISRU with Regenerative Life Support Systems (RLSS) and the discussion of possible agricultural scenarios for lunar and Martian outposts 37 , 104 , 105 , 106 .

As knowledge progressed, researchers saw the necessity to develop more reliable tools to mitigate plant stress and thus improve crop productivity. One of these first approaches was by ref. 107 , who emulated ecological substrate colonization phases in regolith using pioneer species (e.g., Tagetes patula L.) associated with root-colonizing microorganisms. Kozyrovska observed that it took a long time until the substrate was ecologically stable enough to support full crop cycles, though this work did eventually grow plants 107 . These results further strengthen the idea that some regolith amendment was needed to make regolith-based agriculture possible, which steered the scientific community to explore several approaches to “hack” off-world agriculture.

In recent years, exploration of the topic has continued with a broad focus of applications from experiments that explore small-scale early exploration possibilities, challenges, and conditions 74 , 108 to long-term exploration that considers potential of much larger-scale agriculture (e.g., 61 ). Though, even after showing promising potential 64 , 109 , 110 , regolith amendment technologies still seem unable to create a sustainable crop rotation system. These challenges underscore the need for further investigations, especially when it comes to controlling severe pH shifts around the rooting zone stratification (either acidic or alkaline) that directly affect the plant’s physiology 111 , by the presence of elevated or trace levels of perchlorate in Martian regolith-based trials 10 , 74 , 112 or by the need of an active microbiome that is capable of surviving in a regolith substrate, utilizing the substrate and other in situ resources, and reverting them in a continuous way to create a closed nutrient cycle that has both plants and microbiome as the primary energy providers at each end of the spectrum. Most recently, small portions of lunar regolith collected during the Apollo Program were used to successfully germinate and grow Arabidopsis thaliana 113 . This study provided crucial confirmation that lunar regolith does indeed have the potential to function as a substrate for plant growth, albeit with significant stress to this model plant.

Applications and sources of microorganisms in regolith-based agriculture

Sterilization of nearly all surfaces, including biological ones like seeds, is a common strategy in space exploration for a variety of reasons. However, an axenic approach to sustainable agriculture i.e., one in which the plant(s) is/are the sole constituent step of a BFS, is not a reasonable, nor desirable approach in any environment. The origin and success of terrestrial plants are intimately coupled to the microbial cohorts that populate their surroundings and surfaces, affecting them physiologically, genetically, and biochemically throughout their life 114 , 115 , 116 , 117 . Indeed, the region of soil within 1 cm of the root surface, known as the rhizosphere, often contains a significantly more dense and diverse population of microorganisms than bulk soil. With estimates as high as ≈10 11 microbial cells/gram of host tissue with over 10,000 different species present roots are a “hotspot” of bio- and metabolic diversity 117 , 118 , 119 , 120 . These diverse microorganisms impact agricultural yields, plant disease resistance, nutrient utilization, nutrient uptake, ecological robustness, and secondary metabolite production 114 , 121 , 122 , 123 , 124 , 125 , 126 , 127 . So crucial is this relationship, that both plants and microbes have evolved a variety of biochemical pathways to drive the selection and maintenance of these interactions. This population adapts to and influences their host plants both spatially and temporally, making them crucial players which must be incorporated into any model for sustainable agriculture regardless of the ecosystem they will ultimately inhabit 114 , 122 , 124 , 128 , 129 , 130 .

Understanding and manipulating the holobiont, the total collection of the host plant and its microbial cohorts, is key to optimizing plant growth especially in challenging substrates like lunar or Martian regolith. While hormone manipulation, such as the reduction of ethylene production, is a generally useful feature conveyed by some plant growth-promoting (PGP) bacteria, activities that directly modify the growth substrate and/or nutrient availability are likely to be of greater utility in regolith-based agriculture 114 , 117 . PGP phenotypes that could directly impact nutrient availability or regolith composition include: (i) phosphate solubilization, (ii) nitrogen fixation, (iii) iron sequestration and redistribution, and (iv) the formation of soil organic matter (SOM). Phosphate solubilization is a common PGP phenotype observed in the rhizosphere performed by both fungi as well as bacteria. Similarly, bacteria-derived chelators known as siderophores can sequester and redistribute the rich iron deposits within regolith, improving availability of this important micronutrient to host plants. Nitrogen fixation by free-dwelling or nodulating species of bacteria is of particular interest given the limited amounts of this important macronutrient observed in regolith to date, as well as the costs (and risks) associated with shipping solid nitrogen-based fertilizers to a lunar or Martian colony 86 . Finally, rhizosphere bacteria can utilize root derived exudates as well as other exogenous sources of carbon to facilitate the conversion of regolith to SOM.

Though important differences exist between the microgravity environment of LEO and the hypogravity environments of the Moon and Mars, studies aboard the ISS can inform our understanding of some aspects of growth in regolith, such as the composition of available bacteria for formation of a robust microbiome at plant surfaces 131 , 132 . The present approach of seed surface and growth substrate sterilization means that the plant microbiome which does form in these isolated environments will be almost entirely derived from the microbiome of the colonists, or the endophytic bacteria safely protected within the seed coat 133 , 134 . However, even from within this population of primarily human-derived microorganisms, a number of potential PGP microbes have been identified 135 . This underscores the potential to select and develop beneficial microbiomes from the populations most likely to develop in these isolated environments and which have established spaceflight histories. While such studies are ongoing, an alternative or complementary approach will be the introduction of specific microbial cohorts to facilitate RBA, an approach which has been explored in a variety of regolith simulants. Here we review these initial efforts to exploit microorganisms to improve the ISRU viability of Martian and/or lunar regolith with a particular interest in their potential to support plant growth.

Establishing a baseline—microbial composition of regolith simulants

Both environmentally and anthropogenically sourced regolith simulants are likely to harbor microorganisms which can influence the results of RBA research. Sterilization of these simulants to remove these initial populations is problematic due to the limited ability to sterilize bulk quantities for larger research, as well as the potential for various sterilization methods to alter the composition of the regolith simulant. Yet little characterization of the initial microbial composition of these simulants has been conducted to date, despite their potential to impact the results of work conducted therein. Studies by Allen et al. examined the microbial profile of JSC Mars-1A, an early and heavily utilized MRS 136 and identified a number of bacterial and fungal species present in untreated simulant 137 , 138 . Among the eight species of Bacillus they identified were B. megaterium and B. licheniformis , both of which are potential PGP species via improved nutrient solubilization or gibberellic acid production, respectively. Several species from the order Actinomycetales were also identified, including at least one species of Streptomyces . Several fungi from the genera Aspergillus , Penicillium , and Fusarium were also isolated. Aspergilli and Penicillium species may have PGP potential via phosphate solubilization as well as the production of antimicrobial agents to control microbiome composition 139 , 140 . Meanwhile, the presence of Fusarium species is of significant interest, given they are well-associated with a variety of crop diseases 141 . Similar efforts to characterize the initial microbial load and composition of other regolith simulants have yet to be performed, but are important to adequately establish the starting microbiome for plant-microbial associations in RBA research. While standard enumeration assays could provide quick insight into the total number of microorganisms in these samples, species/genus resolution would help identify the potential for PGP phenotypes already present among these populations.

Microorganisms viability in and utilization of regolith simulants

Regolith simulants have been extensively used in research for astrobiology as well as planetary protection, as substrates for a variety of microorganisms exposed to the harsh environments of Mars. For example, several species of methanogenic Archaea introduced into a variety of regolith simulants can survive both desiccation and the hypobaric (low-pressure) environment associated with the surface of Mars 142 , 143 . In these species, metabolic activity, specifically methane production, was restored by rehydration suggesting a model for how microscopic life on Mars could persist via rounds of desiccation and rehydration via intermittent flows of water.

Similar studies were conducted with a variety of bacterial species and confirmed that strains of B. subtilis and Enterococcus faecalis suspended in a variety of regolith simulants were also resistant to extreme desiccation, perchlorate exposure, reduced atmospheric pressure, and Mars-equivalent UV exposures 144 . Regolith analogs have also been used for planetary protection studies, specifically to observe whether bacteria could be transferred from the wheels of a rover to the Martian surface 145 . Taken together, these studies further establish regolith as a viable substrate and reservoir for microorganisms, one that could protect some species over short durations in the case of life support system failures, a potential benefit to RBA efforts.

Based on existing data, both lunar and Martian regolith contain many macro- and micronutrients of benefit to the health of plants and humans, as well as potential industrial applications. In our discussion of existing microorganisms in regolith simulants above we identified several species with the potential to improve plant growth, based on their ability to improve the solubilization of important materials such as phosphate. However, the use of microorganisms to improve the extraction of other essential elements from regolith simulants has also been explored. Work by Cousins et al. explored the potential of JSC-Mars-1A as a biomining substrate for the extraction of iron by several species of bacteria including Acidithiobacillus ferrooxidans , Shewanella oneidensis , and Magnetospirillum gryphiswaldense 146 , 147 . In most cases, the cost-benefit analysis confirmed that the nutrient inputs required exceeded the value of the iron extracted in these studies. However, S. oneidensis did emerge as a promising candidate for the extraction of iron for a variety of applications in a cost-effective manner and could be utilized in an early pre-treatment step.

Further work with A. ferrooxidans utilizing both LMS-1 and MGS-1 as substrates confirmed their ability to improve the solubilization of Si 1+ , Mn 2+ , Mg 2+ , and iron (as Fe 2+ ) suggesting this microorganism may also be of benefit depending on the simulant and growth conditions employed 148 . In this latter study, cultures grown in a clinostat showed a significant increase in mineral solubilization relative to 1G controls. However, given that the microgravity conditions simulated by clinostats can vary significantly from the partial gravity environments on Mars and the Moon, the importance of these enhancements is unclear. Ultimately, the ability to mine essential minerals from regolith could be of considerable benefit to RBA.

Plant growth-promoting microorganisms in regolith

The studies above support the potential of microorganisms to transform regolith into substrates better suited for plant growth. While such bioweathering/bioleaching may occur with greater frequency within the rhizosphere and could provide inorganic nutrients in support of plant growth, they are not due directly to interactions with a host. Yet, the importance and potential benefits of plant-microbial associations are becoming increasingly clear in the development of next generation agricultural solutions here on Earth and will almost certainly be part of a strategy for successful RBA systems off-world. Here we will discuss preliminary regolith-based research which incorporated the two most well-established plant-microbial associations: nodulation and mycorrhizal fungi into regolith studies.

The legume-rhizobia symbiosis supports plant growth via nitrogen-fixation in ~20% of all land plant species and represents a crucial interaction which could minimize potentially damaging environmental inputs of fertilizers 149 . As a result, there is considerable interest in whether lunar or Martian regolith could support this mutualistic symbiosis. Seeds of Melilotus officinalis (sweet clover) have recently been shown to support the formation of active N-fixing nodules in conjunction with Sinorhizobium meliloti 1021 in MMS-1 150 . This study confirmed that nodulation was sufficient to increase total plant biomass accumulation by an order of magnitude relative to uninoculated controls. Species like clover are routinely used to introduce nitrogen and organic matter into soils and could be used to convert regolith into soil prior to farming attempts. Similarly, Rainwater and Mukherjee confirmed nodulation as well as increased growth in seedlings of Medicago truncatula , a model system for symbiosis research, in both MMS-1 and MMS-2 by three different species of rhizobia 151 . While both of these studies have been conducted in regolith simulants of lesser accuracy, they underscore the potential to capture this important symbiosis for sustainable agriculture. Notably, successful nodulation under hydroponic conditions is less established and their benefits on growth are poorly characterized in contrast to a wealth of information from soil research.

While nodulation represents an important and relatively common plant-microbial symbiosis it is far from being the most common of these associations. Indeed, an estimated 75% or more of terrestrial plants are capable of forming associations with mycorrhizal fungi to improve nutrient uptake, sensing, and disease resistance 152 . Such associations are presumed to be among the earliest plant-microbial symbioses to have evolved in terrestrial plants and harnessing this activity would be immensely useful for RBA systems. Preliminary efforts confirm that the lunar regolith simulant JSC-1A is capable of supporting the growth of the mycorrhizal fungi in association with prickly pear seeds (Opuntia ficus-indica ) 153 . Specifically, Trichoderma viride as well as one or more isolates of the genus Glomus, both of which can improve host plant nutrient uptake and/or limit pathogenic infections by deleterious fungi. The addition of mixed cultures of these fungi significantly improved the germination of seeds of O. ficus-indica underscoring the potential for such microbial amendments as a tool for improving cultivation at an additional point (germination) not just in support of vegetative or reproductive growth.

While specific plant-microbial interactions are beneficial, an approach that leverages species and functional diversity is more robust and sustainable over the life of a single host plant as well as for the substrate (regolith) that will sustain crop growth over multiple generations. Decomposers are an excellent example of such microbial systems, functioning similarly to the biomining species described above, but primarily liberating organic material from dead tissues. This activity is a crucial aspect of bioregenerative life support and will become increasingly important as researchers begin to incorporate crops with significant amounts of inedible biomass into our models for off-world food production. With this in mind, Gilrain et al. incorporated decomposers into their food production system by generating compost to supplement the growth of Beta vulgaris (Swiss chard) in JSC-Mars-1A 154 . Duri et al. utilized such decomposers to generate compost as a supplement for samples of butterhead lettuce ( Lactuca sativa ) grown in MMS-1 109 . Their findings suggested that compost may help to modulate cation release, limiting the phytotoxicity of elements like Al3+ while limiting runoff loss to others like Ca2+ and Mg2+. Complementary studies confirmed that the addition of composted material impacted hydrological parameters of the regolith, further limiting the risk of leaching of potential phytotoxins 111 .

Lytvynenko et al. made one of the first attempts to assemble an engineered microbiome for lunar regolith using anorthosite as a lunar regolith proxy 107 , 155 , 156 . These studies envisioned the use of this consortium to extract beneficial nutrients from regolith to support plant growth, in this case Tagetes patula (French marigolds). Among these were an isolate from the genus Paenibacillus (sp. IMBG156) which formed biofilms on the surface of sterilized anorthosite particles. In these biofilms, this strain liberated both Ca 2+ and Si 4+ as well as oxidizing Fe (II) to Fe (III), improving plant access to all three of these ions under conditions that would also support plant growth. Pioneering strains like these could be used to begin remodeling regolith in advance of planting facilitating the first round of growth. Other members of this consortium included known plant growth promoting microorganisms Klebsiella oxytoca IMBG26, Pseudomonas sp . IMBG163, P. aureofaciens IMBG164, and Pantoea agglomerans IMV56. This consortium supported T. patula growth in anorthosite improving germination, survival, and growth, most notably allowing plants to flower, which did not occur without the engineered microbiome in anorthosite.

While preliminary, these various lines of evidence support the potential of incorporating a variety of the plant-microbial associations that began with the earliest terrestrial plants. Ultimately, a systems or holobiont approach to RBA which incorporates select microbial cohorts will integrate more efficiently with any bioregenerative life support system at work in an off-world colony. This would replace the existing strategy of the indiscriminate elimination of all microorganisms which has proven remarkably unsuccessful though clearly, further work in this area is required.

“Best practices” for the future of research in regolith-based agriculture

The body of RBA research available to date consists mostly of preliminary plant growth experiments addressing fundamentally basic topics of agricultural science applied to the Moon or Mars. While this provides important groundwork and insights into the potential for RBA, many of these studies, including our own works, still fail to provide a clear picture of the precise procedures capable of providing successful approaches for regolith-based agriculture beyond Earth. In order to be successful, off-world we need to be able to accurately predict crop yield, even under potentially disastrous situations. Yet there is a significant gap between current research and the successful realization of an RBA system with such reliability. We can summarize these gaps into four broad areas for improvement: 1) Regolith simulant preparation, amelioration, and alteration, 2) evaluating plant growth and response, 3) microbial identification, community development, and response, and 4) environmental controls of the experiments themselves.

However, providing a tightly controlled environment, making accurate regolith simulants, testing plant physiology and genetics, and assessing microbial status all require specialized knowledge and training, can be very expensive, and the equipment needed is often difficult to access. Depending on access to funding and expertise, it may not be feasible to do all these aspects at the same time in every experiment. We highly recommend collaboration as a solution to this issue; however, this option is not necessarily available in every scenario. To help address the gaps both in knowledge and accessibility, we begin by identifying key knowledge gaps in the form of specific questions. We follow these questions with tiered recommendations for experimental design and reporting of results that will assist in filling these gaps. These tiers (Introductory, Intermediate, and Advanced levels) establish the experimental rigor dedicated to each of the 4 areas and are intended to be deployed in a “mix and match” fashion, permitting researchers to address specific RBA knowledge gaps with their research while meeting certain minimum requirements. The distinctions help guide researchers through a structured progression in their work, ensuring that basic concepts are mastered before more complex, nuanced, or technologically advanced investigations are undertaken.

Introductory

These are foundational research activities designed for new entrants into the field. They focus on basic principles and simple experiments that are critical for understanding the fundamentals of regolith-based agriculture. This level is meant to build a solid base of knowledge and skills.

Intermediate

At this stage, the research delves into more complex interactions within regolith agriculture, such as chemical properties and plant responses. It assumes a certain level of foundational knowledge and aims to expand on that by exploring more detailed aspects of plant growth and soil interaction.

This highest level involves sophisticated research methodologies and experiments. It’s aimed at those with a strong background in the field, looking to push the boundaries of current understanding. Advanced recommendations often involve integrating multiple complex factors or innovative technologies to address the challenges of growing plants in regolith.

These tiers are intended to be inclusive, not prohibitive, by providing clear standards and practices for experimental design and publication, that will make it easier for new researchers and their projects to join the RBA community. To better illustrate our intentions and provide some guidance, following this list of recommendations we have also provided a series of decision trees as well as an illustrative case study evaluating the four key areas of RBA questions and their specific tier. Through the act of asking “what is best?” we hope to help establish the current boundaries of our understanding, recommend research practices that bring coherence and an ability to communicate results more effectively in the community, and illustrate examples of some of the ways these recommendations can be applied. Together these key questions, recommendations, and illustrative examples can provide a set of “best practices” intended to help provide greater coherence and focus for RBA research that can begin to fill the gap and bring it to a TRL at which it becomes a reliable component of sustainable off-world agriculture.

Key questions and knowledge gaps

Here is a list of key questions or needs that make up the current knowledge gap of RBA research. This is not an exhaustive list, but a starting point that helps to inform the recommendations that follow. The authors have written this list with their expertise informed by literature and have refined into the questions they deem more pressing. Indeed, some of these questions represent noticeable knowledge gaps which must be addressed before all of our best practices can be implemented as well as questions for which the implementation of the recommended best practices can help provide more coherent answers. Additionally, microbes, plants, and regolith all interact within their environment, thus some overlap exists among questions approached from the perspective of each aspect. This merely underscores the utility of this effort. Even if it were possible to list all the current key questions, the very act of addressing these questions will bring forth more questions all of which will inform the recommendations that follow allowing them to evolve as the knowledge gap is filled. This exercise represents a starting point from which more questions must be asked, research approaches and practices can evolve and knowledge gaps can be filled. Here are specific questions that emerged from this exercise:

Regolith and regolith simulants

Q1. How accurately do regolith simulants currently developed represent actual Regolith?

Motivation: A few disparate studies that evaluate simulant accuracy are available, but most only examine a few simulants and use vastly different approaches for this evaluation. There are also a few reviews that list available simulants for the Moon and Mars covering many simulants (e.g., Duri et al.) but have limited exploration of simulant accuracy to actual regolith 109 . A more thorough evaluation of developed simulants that includes both a more extensive number of simulants and a thorough evaluation of simulant accuracy would be a valuable resource for understanding current simulant limitations, recommendations in simulant development, and a list from which researchers can select simulants most appropriate for the intended study. Though it is also recognized this represents a significantly challenging endeavor as published data or simulant samples are not always readily accessible.

Q2. What data is needed about actual lunar and Martian regolith to better evaluate regolith fertility and how these be measured by current and future robotic missions?

Motivation: Though we do understand much about lunar and Martian regolith mineralogy and chemistry, certain aspects relevant to agriculture are not well constrained. In particular the amount and bioavailability of plant relevant nutrients and phytotoxins, direct measurements of soil pH and salinity, the composition and geochemistry of poorly understood components of lunar and Mars regolith (for example the amorphous portion of Mars regolith and other surface materials), presence of minable in situ resources of fertilizer components not available in the regolith directly. Many of these aspects are difficult to apply to robotic exploration and thus have limited or no data available, but advances in engineering and technology have increased and will continue to increase the ability to measure such characteristics.

Q3. What non-regolith materials may also have agricultural applications and what data is needed to understand potential contribution to viability and fertility

Motivation: This is a continuation of question 2, but applied to other surface materials that could be processed or applied as well. For example, acidic-sulfates on Mars could help regulate the pH of soils or hydroponic fluid, however to adequately understand the viability of such techniques we need data from actual surface materials to better characterize them and simulants that accurately mimic their characteristics in order to test them.

Q4. What agriculturally relevant characteristics are lacking in available regolith simulants and are there viable techniques that can accurately replicate them at appropriate scales?

Motivation: If the comparisons suggested in question 1 can be more thoroughly established, that leads to consideration for simulants applied to RBA studies and what characteristics are not mimicked that may have important agricultural implications. To what degree is it possible to adapt current simulants or develop new simulants that do mimic these characteristics. It is also important to realize that the degree to which this question can be answered is limited by our current understanding of actual regolith and as that knowledge increases it is useful to reevaluate current simulants.

Q5. Which nutrient extraction methods are best correlated and calibrated for regolith materials, or are any of them?

Motivation: Nutrient extraction is used to evaluate not just the amount of nutrient in soil, but the amount of plant extractable nutrient 157 . These tests are not based on direct measures but rather known correlations among certain extracting materials and plant uptake that have been calibrated to fertilization recommendations. However, this correlation is not very consistent among different soil types as the extractants can behave very differently in differing soil conditions, thus different locations often select tests most applicable to major soils in their region. However, such correlations and calibrations have not been established for regolith simulants thus any nutrient or fertility evaluations may or may not provide viable results. A study that examines different extraction methods on different simulants and if they correlate with plant uptake or not is needed for such fertility tests to be accurately evaluated and for resulting recommendations for increasing fertility to be viable.

Q6. What effects do sterilization, and other pre-processing techniques, have on Regolith Simulant composition? How effective are these techniques at sterilizing regolith simulant materials?

Motivation: There are many situations in which it may be useful to sterilize regolith simulants (or at least attempt to) in order to provide a sterile medium for which to begin a study. However, many of these techniques can drastically alter mineral materials. The potential for alteration will differ among mineral type and sterilization method, but we are not aware of any studies that directly evaluate these alterations and the implications on simulant composition and its relevance to actual regolith. It is also difficult to truly sterilize soil-materials and it would be useful to examine the effectiveness of a method compared to the degree of alteration it induces. Though sterilization would be among the most commonly applied processing techniques expected, the same concerns hold true for any processing applied to a simulant to prepare it for a particular study.

Q7. How well do the many ameliorative techniques proposed improve the regolith fertility and how variable is this success among different regolith types?

Motivation: There are many approaches that have been proposed for developing viable materials from regolith. For example, rinsing Martian regolith to remove salts including perchlorates. However, testing such techniques on a Martian regolith simulant that does not contain salts would provide completely useless results. But even simulants that accurately represent Mars regolith salinity would need approaches and evaluations that are comparable among studies or studies that examine multiple simulants. This overall concept holds true for any ameliorative technique attempted: i.e., first and foremost such studies must use a simulant that accurately mimics the relevant characteristics seeking to be ameliorated, and even when that is the case comparison to other studies or among multiple simulants allows provides a more broadly applicable ameliorative solution.

Q8. How does exposure to the experimental conditions alter regolith simulants, how are the alterations evaluated and what implications does this have for actual regolith and how is that evaluated?

Motivation: Similar to the alterations that can be induced from processing techniques referred to in question 6, the alterations that occur as a result of the experiment are also important, though they depend on the intent of the study. However, as weathering or alteration of mineral materials can be slow these changes may be subtle (though not insignificant) and commonly applied techniques (like XRF or XRD) may not be able to measure some changes that are important for plant response. However, XRF and XRD are highly useful in that (partly because they are so common) can provide results more comparable among different studies while techniques more sensitive to small alterations may be more limited in their comparability. Simulants (and indeed most growing mediums) can be highly heterogeneous and thus insufficient replication or sample size can limit the ability to detect patterns. Thus a combination of techniques and adequate sample size are important to consider in determining how to measure changes in simulant characteristics.

Plant response to regolith-based substrates

Q9. In what ways are plant tissues chemically affected as a result of being grown in regolith or regolith simulant, and how might this affect edible and non-edible yield and quality. Which tissues are most and least affected by plant growth in regolith or regolith simulant?

Motivation: Photosynthesis is inhibited 158 and plant morphology and physiology are affected 159 by heavy metals, so both ultimate yield and plant quality varies depending on the elements (and elemental forms) taken up by plants. However, plant translocation of elements is complex, and depends on plant species, environmental content of elements, oxidation/reduction potential, pH, and other factors. Therefore we must explore these effects in regolith to understand how regolith may affect plant and human health in the long term.

Q10. When grown in regolith or regolith simulant based growing mediums, in what ways would plants alter the medium? How might root exudates alter regolith properties over the short-term and long-term? How might regolith simulants alter plants’ relationships with root-colonizing (especially root nodulating) microorganisms, and what key factors could cause these effects?

Motivation: We have established that soil quality has direct effects on plant physiology, growth, and quality, however plants also have reciprocal effects on the rhizosphere. Plant roots produce exudates that contain metabolites and a wide variety of compounds, which alter chemical and physical properties of soil, help maintain and support microbes, and have critical impacts on long-term plant health 160 , 161 . Therefore, to understand the long-term effects of using regolith for agriculture, we must elucidate how regolith may change over time as a result of agricultural use.

Q11. What avenues are most appropriate to increase organic carbon content in regolith or regolith simulant based growing mediums? What stable organic amendments are most effective at both supplying organic carbon for plants and improving the texture of the substrate for supporting plants? Are the avenues actually helpful at improving the viability of the mediums?

Motivation: Soil carbon is required for plant and microbial growth, however its availability in the soil is affected by soil amendments, root exudates, microbial activity, and other factors 162 . Therefore we must find methods to supply enough carbon to regolith to meet the needs of plants and the rhizosphere microbiome, and understand how organic amendments affect RBA.

Q12. Do current soil nutrient extraction tests applied to regolith or regolith simulants correlate sufficiently with plant uptake to determine reliable fertilization recommendations?

Motivation: fertilizer recommendations are made using soil/nutrient testing; however these tests may not provide accurate or adequate fertilizer recommendations when used on regolith. Therefore, we must examine whether these tests are accurate and work to optimize them for regolith applications, such as by using regolith simulants with known chemical properties to calculate the ideal dose of each nutrient.

Q13. As we consider RBA compared to hydroponic methods, what crop species may be particularly well-suited for RBA? Do these crops fulfill the needs of astronauts, or is further crop selection necessary? Are these crops that meet current crop selection criteria feasible to use in RBA, when other considerations (such as the need for food processing) are considered?

Motivation: Multiple studies have established a consensus of logical plant choices that fill nutrient requirements for future off-world agricultural efforts 131 . However, these are based on the assumption of fully hydroponic systems, and use of regolith may alter what considerations are most relevant. Therefore we must reconsider crop selection needs and reevaluate whether these crop lists are usable with RBA.

Microbial community identification and response to regolith-based substrates

Q14. What is the endogenous microbial composition of the common regolith simulants?

Motivation: A basic understanding of the existing microbiome of regolith simulants would help distinguish between substrate effects and microbial ones. As sterilization of large amounts of regolith simulants for scale-up studies is not possible, identifying these microbes becomes an important step moving forward.

Q15. Does this endogenous population significantly alter these simulants post-acquisition?

Motivation: Over time, the endogenous microbiome of the simulants may alter regolith composition. In other words, regolith simulants, stored under Earth conditions, will age differently than regolith on Mars or the Moon. Although such changes are likely to be slow it should still be part of our consideration as regolith becomes soil, in part, through the actions of microorganisms.

Q16. Do these simulants contain plant growth promoting microorganisms?

Motivation: The potential that plant growth promoting bacteria are already in regolith simulants may be impacting plant growth studies already and a baseline needs to be established.

Q17. How well can plant-associated microorganisms be cultivated in regolith?

Motivation: At present, there is no information on how the rhizosphere and phyllosphere of plants grown in regolith simulants may vary from controls grown in more traditional soil substrates, or how this affects plant-associated microorganisms. Low nitrogen levels in both Martian and lunar simulants, for example, may select for nitrogen-fixing microbes from the surroundings, even if they are not already present in the simulant. Understanding how these microbiomes vary as a function of substrate is crucial to implementing a cultivation program that utilizes microorganisms.

Q18. Does regolith alter the phenotypic behavior of plant-associated microorganisms?

Motivation: Closely related to Question 4, not only may there be differences in microbiome composition, but the phenotypes of specific microorganisms may vary based on regolith compositions. For example, the low nitrogen, high iron concentrations found in Martian regolith and its simulants may alter the behavior of non-nodulating nitrogen-fixing bacteria.

Q19. What challenges does regolith pose to the extraction and identification of organic compounds for evaluating the chemical composition of the rhizosphere?

Motivation: Regoliths (and simulants) are composed of materials which tend to complicate the extraction of organic compounds. This can complicate analysis of the rhizosphere chemicals both from plants as well as bacteria. Refined protocols are needed for this process for the different stimulants.

Q20. What challenges does regolith pose to the extraction and identification of bacteria or environmental DNA for evaluating the chemical composition of the rhizosphere?

Motivation: The challenges associated with the extraction of organics from the simulants will be similar for the extraction of DNA and possibly intact bacteria. This would represent an extra challenge for metagenomics and other microbial characterization approaches. Refined protocols are required for this process for the different simulants.

Q21. How does the microbiome of adjacent surfaces influence the endogenous microbiome of regolith (and simulants)?

Motivation: Off world-agriculture, regardless of its site, will occur in highly enclosed spaces for the foreseeable future. Such environments are prone to significant mixing of microbial populations between the inhabitants (human, plant, etc.) as well as the surfaces they encounter. Migration of microorganisms to regolith (and simulants) from biotic and abiotic sources in the environment could be an important source of both mutualistic as well as pathogenic cohorts. Indeed, prior studies have already identified migration from the human microbiome into the rhizo- and phyllosphere of plants aboard the ISS.

The growth environment

Q22. What is an acceptable balance of atmospheric conditions (composition, atmospheric pressure, humidity, etc.) for off-world closed food systems in a hypogravity environment such as the Moon or Mars? What considerations are needed for the interactions among plants, microbes, regolith, crew members, and the outside environment?

Motivation: The conditions conducive for agriculture in off-world systems must be investigated in order for researchers to, 1) create accurate cost projections, 2) to methods for maximizing yield, and 3) to enable engineers to design the systems that will support these crops. Researchers on Earth must also consider the air environment, especially the carbon dioxide concentration and volatile organic compounds, when undertaking analog experiments that include plants.

Q23. Similar to the aforementioned atmospheric conditions, which irrigation strategies are most effective for maintaining optimal hydration for growing plants in regolith simulant? What trade-offs exist for each irrigation strategy, and how can the effects of these trade-offs be minimized?

Motivation: Irrigation can have drastic effects on plant growth and development, and optimizing irrigation strategies for RBA will be vital. Water will be a limiting resource in space environments, making water conservation a high priority. Furthermore, the leaching proprieties of water should also be considered. Heavy or low-flow systems, systems that will only affect the rooting zone or the bulk area of the substrate, and strategies that are either bottom-up or surface sprays will have different impacts on nutrient leaching rates. Each approach will have different effects on the overall nutrient accessibility to the plants and will alter the substrate’s pH, thus influencing microbiome recruitment.

Q24. What sustainable management practices (e.g., no-till vs conventional till, or other cultural practices) applied to terrestrial agriculture may also be applicable to RBA? What are the direct and indirect effects of these management practices when applied to RBA?

Motivation: Thus far, no study has evaluated the potential benefits of conventional agriculture practices in RBA systems. Tilling is an excellent example as it may be a necessary strategy for lunar and Martian agriculture due to the low granulometry of each substrate. One downside of tilling is that nitrogen-fixing bacteria are exposed by revolving the lower tiers of the substrate, and this exposure could cause microorganism death, which would threaten the balance of the nitrogen cycling system. As tilling may be an early strategy for planting seeds in an RBA scenario before a microbiome is introduced, further studies are necessary to use conventional agriculture techniques and evaluate their transferability benefits to RBA systems. Other management practices must be explored to identify areas for improvement in RBA. Furthermore, research should prioritize practices that are realistic and feasible for use in real off-world settings.

Q25. What technology advancements would need to be developed or adapted in order to create these systems and how might multiple technologies be integrated while minimizing the risk of system failure?

Motivation: Much research has been done into hydroponics and other methods for growing crops in controlled environments, however this research has not thoroughly explored the possibility of using multiple methods (hydroponics, RBA) alongside each other, or in tandem for the same crop. Therefore further research must look at controlled environment technologies and other growing techniques, see what can (and cannot) be used with RBA, and consider the most efficient approach.

List of recommendations

Designing, selecting and monitoring changes to regolith simulants.

Access (including presumed future access) to Martian and lunar regolith is extremely limited and necessitates the use of simulant regolith materials used as proxies for regolith research. But for a simulant regolith to provide useful results, it must sufficiently mimic relevant characteristics of the actual regolith material. It is not possible to mimic every characteristic of a material, but characteristics important to the application can be the primary focus and the extent to which the simulant materials used actually reflects particular characteristics of actual regolith is used to organize the introductory, intermediate, and advance tiers of recommendations. Consideration for availability and accuracy of existing simulants is considered. Also important to consider is any treatments (e.g., sterilization) the regolith will be exposed to within the experimental design, how such treatments will affect the regolith, and what limitations that places on conclusions that can be made for some aspects of the experiment. Finally, using appropriate and consistent methods (or at least methods that can be readily compared among different studies) for tracking changes that occur to the regolith over the course of the experiment are each important to consider. Some examples of resources that provide lists of available simulants include the Planetary Simulant Database hosted by Colorado School of Mines ( https://simulantdb.com/ ), the Astromaterials Research and Exploration Science (ARES) lunar simulant project hosted by NASA ( https://ares.jsc.nasa.gov/projects/simulants/ ), and a recent review from ref. 22 (Table 2 ). Additionally, Figs. 1 – 3 provide examples for how these recommendations should be considered during experimental design.

This is a decision tree describing questions and recommendations for designing RBA experiments, with an emphasis on regolith chemical and physical properties. The green boxes (left side) include questions researchers might consider when designing their experiments and choosing their methods. Arrows indicate which recommendations are appropriate, depending on researchers' answers to the questions in the green boxes. The blue boxes (middle of figure) indicate the recommendations that would be suitable for their research. The purple boxes (right side) indicate additional considerations and analyses that might improve the quality of research. The large downward-pointing arrow illustrates how the funding and time requirements of the recommendations listed significantly increase from the top to the bottom of the figure.

This is a decision tree describing questions and recommendations for designing RBA experiments, with an emphasis on plant growth and quality. The green boxes (left side) include questions researchers might consider when designing their experiments and choosing their methods. Arrows indicate which recommendations are appropriate, depending on researchers' answers to the questions in the green boxes. The blue boxes (right side) indicate the recommendations that would be suitable for their research. The large downward-pointing arrow illustrates how the funding and time requirements of the recommendations listed significantly increase from the top to the bottom of the figure.

This is a decision tree describing questions and recommendations for designing RBA experiments, with an emphasis on microorganism evaluation. The green boxes (left side) include questions researchers might consider when designing their experiments and choosing their methods. Arrows indicate which recommendations are appropriate, depending on researchers' answers to the questions in the green boxes. The blue boxes (middle of figure) indicate the recommendations that would be suitable for their research. The purple boxes (right side) indicate additional considerations and analyses that might improve the quality of research. The large downward-pointing arrow illustrates how the funding and time requirements of the recommendations listed significantly increase from the top to the bottom of the figure.

Introductory recommendations for regolith

For experimental designs in which the composition and characteristics of regolith is secondary to other aspects (for example needing a sterile medium to examine specific aspects of plant-microbe interactions) it may be appropriate to select or design simulant regoliths that only roughly represent a Martian or lunar composition. For example, a study focusing on the capillary behavior of water at Mars-like gravity would need to adequately mimic porosity and permeability but depending on the particular aspects being examined may not need to exactly mimic mineralogy, thus a greater variety of materials can be feasibly used. A study that is testing the endogenous microbial composition of the common regolith simulants the selection of simulants is not based on the accuracy of the simulant as much as the commonality of its use in the literature.

For the Moon, a highland-like regolith can be roughly represented from crushed anorthositic materials (similar to that applied by Lytvynenko et al. 156 ) while the lunar mare can be reresented with a roughly basaltic composition. Mars, roughly basaltic materials crushed to represent Martian soil are adequate in work where highly constraining the composition is not required. There are commercially available materials that can serve this purpose as well (see resources above) and may be a viable solution where raw materials cannot be obtained or processed. Two existing Martian simulants that fulfill this requirement include the JSC-1a Mars and the Martian Mojave Simulant (MMS) as these may be more available or more affordable. For example, two variations of the MMS (MMS-1 and MMS-2) are available from The Martian Garden ( https://www.themartiangarden.com/ ) and can be a useful resource. However, it is important to have awareness of the limitations of these compared to Mars for example the high alteration that JSC-1a source rock has been exposed to and the lack of important components such as sulfate minerals and other salts in MMS (and its variations). Once selected or designed, it is important to provide detailed description of the design protocol and of any processing (e.g., sterilization) used to prepare the simulant for the experiment and to consider the effects this processing may have on the conclusions that can be drawn from the results. Depending on the questions being addressed, details of any visual or more readily measurable changes to the simulant (i.e., soil pH or EC) is also recommended though what is measured is expected to vary significantly depending on what is being tested and what methods are accessible with available equipment and funding.

Intermediate recommendations for regolith

The middle-level recommendations focus on bulk composition and general physical properties. For research questions where mimicking the bulk composition of the regolith requires greater accuracy, the selection or design of a regolith is an important consideration. For example, a study directly comparing hydroponic vs. regolith-based approaches for different crops would need to accurately reflect the bulk composition and general physical properties of actual regolith.

The specific characteristics that are recommended for a Mid-level approach include bulk chemistry and mineralogy, particle size distribution, and cohesive and compressive strength. These are characteristics for which there is an abundance of data for both the Moon and Mars and methods available to feasibly reproduce at scales relevant to agricultural studies. This can be achieved by designing a simulant from a mixture of appropriate components determined by examining available data 19 , 129 . However, obtaining appropriate materials can have high time and accessibility constraints which make this more difficult, however there are commercially available simulants that adequately represent bulk composition that can also be used 61 . Whether designed or purchased, the simulant needs to be analyzed to evaluate its accuracy and demonstrate that the accuracy is adequate for the particular research questions being addressed. The methods used to analyze the simulant accuracy need to be directly comparable to data available from actual regolith for example elemental oxide composition obtained by XRF or bulk mineralogy from XRD and comparable PSD (ASTM D6913, ASTM E2651, or commercial particle size analyzers) and penetration (ASTM D3441) tests to understand physical properties. Additionally, a standardized method of comparing these results in a way that scores or compares the simulants is recommended, though there is not a currently consistent standard. One approach that could become the standard (and has been applied to a variety of simulants) is the calculator of a figure of merit (FOM) (e.g., Schrader et al. 163 ; Metzger et al. 164 ) 19 , 62 , 129 .

Other mid-level aspects involve methodologies used to examine changes to regolith simulants due to pre-processing or as a result of the experiment itself. Again, the methods recommended here are those that focus on changes to bulk composition and characteristics. For example, a study examining the effects of various sterilization techniques on bulk regolith properties would need to apply appropriate methods for examining bulk changes. Though this would not capture more subtle changes that are discussed in the High-Level recommendations, those changes that can be examined in such bulk methods do provide useful information to address such questions. Similar to the Introduction-Level any pre-processing treatments of the regolith need to be described in detail, additionally the regolith should be analyzed before and after this treatment using methods appropriate for evaluating bulk composition and general physical properties (e.g., XRF, XRD, etc.) with similar recommendations for measuring bulk changes that occur from the experimental conditions.

Advanced recommendations for regolith

High-level recommendations focus on targeted compositions or characteristics. The reproduction and analysis of these characteristics requires greater access to materials, funding, time and expensive instrumentation limiting the accessibility of these methods. However, this level of accuracy is needed to address certain questions. For example, studies that seek to understand the effects of Mars-like salinity and the effectiveness of various ameliorative techniques require mediums that accurately mimic a Mars-like salt profile. However, this requires either designing or significant alteration of currently available simulants which is both time-consuming and expensive. It also represents a characteristic about which there is somewhat limited data making it difficult to truly determine the accuracy of a simulant compared to actual regolith.

For studies that examine a more targeted characteristic of a regolith (rather than bulk chemistry), it is recommended that an appropriate simulant be specifically designed. Depending on the characteristic, it may be possible to adapt commercially available simulants (either by the seller or the purchaser), but though this may be more feasible than developing a new simulant it can still be expensive. In either case, both the targeted characteristic and bulk characteristics need to be appropriately representative, so the mid-level recommendations are still under consideration in addition to these high-level recommendations.

Depending on the experimental approach, it may also be possible to isolate a particular characteristic which may alleviate the need to represent the bulk properties in addition to the targeted property. For example, using a generic potting soil with Mars-like salts introduced which may be more feasible than designing an entire simulant. Whatever the approach, the simulant or simulated conditions need to be analyzed for accuracy and demonstrated to represent that characteristic (i.e., specific analysis that compare simulation to target) as adequately as is feasible at the necessary scale.

The remaining high-level recommendations focus on methods used to analyze changes to the simulant weather from pre-processing treatments or the experiment itself. It is still important to track changes to the bulk composition and so any targeted analysis is recommended to be done in addition to those that evaluate bulk changes. There is a great diversity of techniques that are available to examine targeted characteristics such that it is not possible to determine a certain set of techniques that should be used every time or space to summarize all techniques available. The technique most appropriate will heavily depend on the particular characteristic and the goal of the study in mind. Some examples of these more specialized techniques include electron microscopy (EM) and computed tomography (CT) which allow for 3-D imaging of the changes to the rhizosphere soil characteristics compared to bulk soil (Gregory and Hinsinger 1999). This can range from relatively simple and accessible EM techniques such as Scanning EM (SEM) or Transmission EM (TEM) to much more expensive and difficult to access approaches such as Focused-ion-beam SEM (FIB-SEM). Structural changes, especially those in highly disordered phases common to soils, can also be examined through a variety of X-ray synchrotron techniques (which are extremely expensive and specialized). It is recommended that care be taken to select techniques appropriate to the research questions being addressed by a thorough examination of the literature and consultation with other researchers especially when such expertise is not directly available within the research group attempting the study and applied to samples before and after preprocessing or experimental treatments.

Measuring plant response to regolith-based substrates

Plants grown in regolith or regolith simulant have complex morphological, physiological, and biochemical responses. In order to evaluate the effects of regolith simulant on these responses, researchers must carefully manage the plant growth environment (air, water, nutrients, and other conditions) to make accurate causal inferences about RBA. More detailed recommendations specific to the environment are provided below, but it is also emphasized here due to the significant effects environment has on plant response and the importance of plant response as a measure of the viability of an off-world agriculture system.

In addition to the growth environment, many other factors such as plant genetics, associated microbiome, variation in simulant characteristics can influence plant response. Replications, especially over time, can also help to minimize the influence of these effects when analyzing plant response variables. In turn, as much as plants are affected by the variables, they also affect the variables including the regolith and microbiome. Additionally, techniques used to amend regolith simulants in the attempt to improve plant response or yield will change the nature of the simulant in ways that are important to quantify. Potential alterations must be considered when designing regolith simulant experiments. For example, as mentioned in the key questions above, research must be done to understand how plant roots and root exudates may cause “weathering” of regolith samples, to understand how fertilizer amendments impact the chemical and microbial properties of regolith, and to assess how other management practices affect the regolith simulant and microbiome (Table 3 ).

Introductory recommendations for plants

Many plant morphological and physical responses must be measured to get a holistic perspective on the effect of regolith, for any regolith simulant experiment. Plant species and cultivar should be reported, as well as the seed source (including company, location, and date). At the beginning of the experiment, germination success rates (expressed as a percentage) should be evaluated, and researchers should observe whether these seedlings are morphologically different from expected/normal. As they grow and develop, these plants should have measurements taken to quantify plant growth, such as plant height or average crown diameter (cm). At the end of the growth period, researchers should also measure the total mass of the resulting plants. Researchers should evaluate shoot fresh mass (SFM) and root fresh mass (RFM) (if it is possible to clean the roots of substrate), and after drying the samples, they should also measure shoot dry mass (SDM) and root dry mass (RDM).

If plant development includes reproductive stages (flowering, fruiting), this should be reported in detail. Important data include approximate growth period (days or weeks) before flower development was observed, average number of flowers and fruits per plant, size of fruit (length and diameter) and fruit mass (g). Observations should be recorded about whether fruits and flowers developed normally or abnormally compared to what is expected for the species or cultivar.

Intermediate recommendations for plants

Plant species, seed source, germination rate (%), and plant growth measurements (plant height, crown diameter, SFM, RFM, SDM, RDM) should be reported, as listed in the “basic-level” recommendations. Plant leaf area (cm 2 ) should be measured using a leaf area meter, leaf scanner, image processing software, or another tool. To evaluate plant physiology, stomatal conductance (mmol m −2 s −1 ) should be evaluated, especially if there is an a posteriori phytohormonal analysis of the samples (e.g., stomatal conductance with leaf abscisic acid concentrations). Stomatal conductance describes the rate of carbon dioxide entering or water vapor exiting through the stomata of a leaf, and depends greatly on carbon dioxide concentration and vapor pressure deficit. Leaf area (cm 2 ) and shoot dry mass can be used to calculate shoot leaf area, which quantifies the average leaf thickness per plant.

If reproductive stages are observed, detailed data should be collected (as described above) for growth period (days or weeks) before flower development, average numbers of flowers and fruits per plant, size of fruit (length and diameter), fruit mass (g), and flower/fruit morphology should be visually assessed.

Advanced recommendations for plants

Plant variables should be evaluated as described in the “mid-level” recommendations. Plant growth measurements (plant height, crown diameter) should be taken at regular intervals throughout the growth period, and measurements at harvest should include leaf area (cm 2 ), stomatal conductance (mmol m −2 s −1 ), SFM, RFM, SDM, and RDM. Additional measurements should evaluate chlorophyll content and relevant secondary plant metabolites, like anthocyanin content. This can be done with a SPAD leaf sensor or with tissue compositional analysis.

If reproductive development is observed, data should be collected as described in the “basic” and “mid-level” recommendations. Additional postharvest measurements should be collected for edible fruiting crops. Alongside fresh weight, fruit size (length and diameter), and average fruit number per plant, tissue should be tested for BRIX (sugar content) and anthocyanin content. Other species-specific fruit quality measurements should be taken, including nutritional content for key nutrients such as vitamin C (though key nutrients vary per species) 165 and capsaicin content (to quantify spiciness for crops like peppers). It is encouraged to test germination percent of any seeds that are produced.

Identifying the microbial community and monitoring response

Microbial populations shape and are shaped by soil across our planet. Their near ubiquitous distribution stands in stark contrast to the Martian or lunar surfaces which are likely devoid of life, or if it does exist, persists in only rarified locations. As all regolith simulants are terrestrially derived, they are all inaccurate from a microbiological perspective as they almost certainly contain an associated population of microscopic bacteria, eukaryotes, and archaea. The aseptic preparation and packaging of these simulants at production sites is unreasonable from a logistics perspective. Sterile procedures are also not reasonable from the perspective of most plant growth projects. Indeed sustainable agriculture in regolith systems will almost certainly depend on the incorporation of specific microbial cohorts to leverage the benefits described earlier in this text (e.g., nitrogen fixation, bioweathering, etc.). Therefore, a gnotobiotic, or knowing the identity of all microorganisms within the regolith, with an aim towards microbial management, is a more reasonable approach than a sterile one.

However, other than an early evaluation of JSC-1A, little information on the microbiomes of either lunar or Martian regolith simulants are available. This represents an obvious area of concern as the presence of specific microbial cohorts, either pathogens or mutualists, would significantly impact any plant growth studies performed in these simulants. Moreover, given the aforementioned potential for microorganisms to transform regolith, the endogenous microbial community of these simulants could continue to alter composition post-acquisition depending on the mechanism of storage. This lack of information regarding the starting microbiome composition represents a significant knowledge gap which needs to be addressed for research of plant growth in regolith . Addressing this concern at the very least should be part of the basic microbial considerations of any ongoing plant growth research. Here we will outline specific experimental considerations that may prove useful for both small as well as large scale studies. The former can often be performed in magenta boxes under sterile conditions, while the latter are often open air and therefore susceptible to contamination by the microbiome of the environment. In the case of a closed loop habitat like a lunar or Martian colony this will likely be endophytes from other plants as well as the endogenous microbiome of the colonists, or any other animals present.

Here we discuss several best practices for including microbes into in situ resource utilization studies with lunar and Martian regolith simulants. As above, we have attempted to categorize these practices with the goal of balancing encouragement of new regolith biology research while providing increased rigor to experimental design and data collection. In the process of developing these best practices, specific research questions which need to be addressed by the regolith research community for further progress in this area emerged and have also been included here (See above section “Key Questions and Knowledge Gaps”).

Introductory recommendations for microbiome

The vast majority of the current plant growth studies in regolith simulants pay little attention to the existing microbiome of the simulant, or consider the use of microbial partners for improving growth. However, leveraging the advantages provided by the incorporation of microbial partners is a research area we predict will experience significant growth over the next few years. Given this likelihood, we propose some simple parameters to eliminate or define the existing microbiome as well as minimum data that should be reported during inoculation studies. As the potential impact of the microbiome on plant growth and development is crucial, even studies not focused on the use of microbial partners should consider these parameters in their experimental design.

For small-scale studies, to be performed aseptically, such as in a Magenta box or other culture vessel, substrates should be sterilized by autoclave or other approved source that will limit changes to simulant mineralogy.

Studies incorporating fungi or bacteria need to include an accepted measure of the inoculum size, or the number of viable units being added. This can include colony-forming units in the case of non-filamentous microorganisms, or total chlorophyll as an approximation for filamentous cyanobacteria such as A. cylindrica 166 . Methods for such inoculations are readily available, and Heydarian et al. is a good example of this 167 .

As an alternative to the use of live microorganisms, microbe-derived biomass (algae, cyanobacteria, etc.) can be employed as a biofertilizing agent. Methods for calculating the dried biomass should be used to characterize how the simulant has been amended as described by ref. 168 .

For large-scale studies, sterilization of all regolith may not be feasible, therefore an accounting of the major species of the microbiome should be referenced if one is available. The lack of such a reference is a notable knowledge gap in the current research .

Intermediate recommendations for microbiome

In contrast to the introductory parameters, our mid-level protocols are intended to address studies focused on the direct investigation of plant-microbial associations. This can be through the use of the existing regolith simulant microbiome, or the intentional introduction of one or more defined species of microorganisms for gnotobiotic studies. This level builds on the introductory parameters, meaning that the microbiome of all simulants should be defined or eliminated by sterilization. At this level, there is no significant distinction between the best practices of small- and large-scale studies; only the sampling size between the two scales should be a consideration.

Observing relative densities of the major cultivable microbes along the rhizosphere between regolith grown samples and controls. A viable procedure for this has been described by ref. 169 . Such assays would need to be performed at LEAST in triplicate for each treatment type.

Characterizing the major cultivable microorganisms as potential plant growth promoting pathogens through plate-based methods, i.e., selective culture media. A summary of viable plate-based methods for the identification of plant growth promoting bacteria (PGPB) is available in ref. 135 . This should be followed with inoculations of plant seeds to confirm PGP activity.

Advanced recommendations for microbiome

Studies at this level move beyond simply identifying the most common inhabitants of the microbiome as well as their potential to improve plant growth, as defined by the mid-level parameters. Rather, high-level studies focus on understanding the temporal and spatial changes both microbiological as well as chemical within the rhizosphere or phyllosphere, the site of plant-microbial associations. Such studies are at the cutting edge of the plant research more broadly and their incorporation into regolith would be evidence that this area of research has indeed “arrived”. At this level, there is no significant distinction between the best practices of small- and large-scale studies; only the sampling size between the two scales should be a consideration.

Determining the spatial distribution of major cultivable bacteria across the root surface as well as distally in the regolith sample should be determined using procedures like those of ref. 169 .

Metagenomic characterization of the phyllosphere, rhizosphere and distal soil using established methods and primers. Common primers for metabarcoding include 16S (prokaryotes and archaea), 18S (protists), and ITS (fungi). Regolith chemical composition is likely to complicate isolation of DNA and an optimized approach needs to be developed. Electrophoretic approaches and isolation methods associated with iron rich substrates may be of particular assistance.

Extraction and analysis of the chemical composition of the rhizosphere. As with DNA extraction, such isolation is likely to be limited by regolith composition and will need to be isolated.

Performing KEGG metabolic network analysis based on identified rhizosphere metabolites to determine potential contributions to plant growth and long-term impacts on soil health.

Recommendations for designing and tracking variables in the growth environment

The growth environment has a significant effect on plant response, microbiome characteristics, and regolith alteration. In order to evaluate the effects of the experimental variables on the intended samples and separate them from the effects of non-experimental or unintentional variables, researchers must carefully manage the plant growth environment (air, water, nutrients, and other conditions) to make accurate causal inferences about RBA. If these tools, facilities, or methods are not within the scope of an experiment, we strongly recommend collaboration with other researchers. To minimize confounding variables, regolith-plant experiments should be done in a temperature-controlled greenhouse or controlled environment growth chamber. Controlled environment (CE) growth chambers are ideal because of their ability to maintain careful setpoints and their flexibility for a variety of environmental conditions. Additionally, replications over space and time can reduce variability in plant experiments, and should be used for regolith simulant experiments even when regolith simulant volume is limited. Ideally, one CE growth chamber would be treated as a replicate, and experiments would be replicated between several growth chambers. Less costly alternatives to this include repeating an experiment over time in one growth chamber, or transferring plants between CE growth chambers to minimize confounding environmental effects (Table 4 ).

Introductory recommendations for growth environment

These guidelines express the minimum frequency at which data should be taken. Dry bulb temperature (degrees Celsius) should be measured at least twice per day–once during the light period, once during the dark period–using a temperature sensor that is shielded from light and moisture and placed at canopy-level and control within limits, 10 degree C fluctuations. Atmospheric moisture should be measured as percent relative humidity (RH%) and controlled within limits, and data should be collected at the same frequency as dry bulb temperature. Carbon dioxide (CO 2 ) substantially affects plant growth and development, and although many plant growth chambers do not include CO 2 -controlling equipment, it is recommended that a CO 2 sensor be installed, and CO 2 concentration should be measured hourly throughout the growth period. Air velocity (m s −1 ) should be measured at the canopy level at least once during the experiment. Watering methods should be carefully detailed in the resulting publication, including the water delivery method (over top, subirrigation, etc.), watering frequency and amount, and pH/EC. If nutrients are applied, these should be measured in mg L −1 of liquid and total mg per plant if granular. Frequency of application should be described, and if liquid, pH of nutrient solution should be reported 165 .

Lighting also greatly affects plant growth and development, therefore at a minimum, light duration (photoperiod, hours per 24 h) and light intensity should be measured. Light intensity is expressed as Photosynthetic Photon Flux Density, PPFD (μmol m −2  s −1 ), where several measurements are taken at canopy height, to find the average light intensity of the growing area. Vertical light gradients depend on many factors, such as chamber size, lamp type, and lamp distribution, so light intensity data should be recorded at the beginning of the experiment and periodically as the plants grow taller. The frequency of this data collection depends on the rate of shoot elongation and the duration of the experiment, but at minimum this data should be collected from sensors placed at the lowest and tallest average plant height. When plants are grown at a greater distance from the lights, there is a less severe vertical light intensity gradient, which results in a more uniform growing environment (i.e., growing plants several meters’ distance from the light source is preferable compared to growing plants only a few dozen centimeters from the light source). Furthermore, when light fixtures are placed close to the plant canopy, this causes greater environmental variation between the place directly underneath the light fixture and the area surrounding this place. These factors should be taken into consideration during experimental design, and therefore accurate data must be reported in the resulting publication(s). It is recommended that authors include data for the distance (cm) between the tallest plants and the light source, and the standard deviation between PPFD readings collected from points across the growing area.

Environmental variables should also include any other pre-treatment of regolith simulant, including whether it was sterilized (and the sterilization method used), the amount of simulant used in each sample (volume and mass), and any nutrients or other amendments added to account for post-sterilization leaching.

Sensor calibration is key to ensuring accurate environmental measurements, and whenever possible, several sensors should be cross-checked to ensure they produce reasonably similar results (especially for light sensors). Sensors should be calibrated regularly, according to the manufacturer’s procedures and recommended frequency. Other useful reporting guidelines include those developed by the NCERA-101 Committee on Controlled Environment Technology and Use: minimum guidelines for greenhouses, and minimum guidelines for growth rooms and chambers, and the guidelines for greenhouses in ref. 170 . Other useful resources, such as Katagiri provides recommendations for building a more affordable, high-quality custom-built growth chamber 171 .

Intermediate recommendations for growth environment

The basis of these environmental variables is similar to those outlined above, in the “basic-level” recommendations, and greater frequency is encouraged. Dry bulb temperature (degrees Celsius) and relative humidity (%RH) should be measured several times during the light and dark period. We recommend that researchers use relative humidity and dry bulb temperature to calculate vapor pressure deficit (VPD, in kPa) within the publication. Carbon dioxide concentration (μmol mol −1 ) should be measured hourly, at a minimum. Air velocity (m s −1 ) should be measured at the canopy-level once daily. Watering methods should be reported as outlined in the “basic-level” recommendations, with some additions. Before any fertilizer is added, water type (feed water, deionized water, Ultrapure water) and its pH and EC should be reported, and water quality testing is recommended. Additionally, leachate should be collected and evaluated for pH and EC at the beginning and end of the growth period. Nutrients applied should be reported as described above, and any pre-treatment of regolith simulant should also be described in detail.

Lighting should be evaluated and reported including photoperiod (h), light intensity over time, and light quality. Light intensity should be expressed as PPFD (μmol m −2  s −1 ), and this data should be collected at canopy level as the plant grows, at least four times throughout the plant growth period, or more often if the plant height is rapidly increasing. Light quality is described as the spectrum of wavelengths emitted by the light source, for all wavelengths in the photosynthetically active radiation range (between 400 and 700 nm). It is expressed as a spectral graph, showing the PPFD of each wavelength. This data is often listed in the product details for the light bulb/diode array, and can also be measured by a spectroradiometer.

Advanced recommendations for growth environment

At this level, similar morphological and physiological observations should be made as are listed above, though with an increased frequency and with some additional variables. Dry bulb temperature (degrees Celsius) and relative humidity (RH%) should be measured at least every 10 min, and we recommend that researchers use these values to calculate vapor pressure deficit (VPD, in kPa) within the publication. Carbon dioxide concentration (μmol mol −1 ) should be measured hourly at a minimum, and air velocity (m s −1 ) should be measured once daily. Watering methods should be reported, and water quality tests should be conducted on the water before fertilizers are added. Researchers should report the nutrients applied (mg L −1 if liquid, total mg per macronutrient/micronutrient per plant if granular) and frequency of application. It is recommended that leachate be collected over time and repeatedly tested for pH and EC. To quantify how much nitrogen (a key macronutrient for plant growth) is retained in the substrate, we recommend that researchers measure the volume of leachate produced by each plant and use this to calculate the amount of nitrogen each plant receives. This also will indicate how much water is available to the plant and will aid in understanding the root environment.

Light reporting should include photoperiod (h), light intensity over time (μmol m −2  s −1 , at least four times over the growth period), and light quality (expressed as a spectral graph). Any other light treatments should be described in detail (such as end-of-day far-red radiation and night interruption), including the spectrum, duration, and time of application.

Applying the recommendations

The central focus of what has been discussed thus far has been the suggestion of primary models from which current or future investigators in the RBA field can use not only to be able to generate standardized datasets but also as a tool with which they will build their experimental designs based on their limitations, strengths and potential to collaborate with other researchers.

The three decision trees (regolith, bacteria, plant) represented in this section create straightforward paths for prospective authors to develop their experimental designs welcoming the standardized tiered system suggested in section 5.0. Each tree serves as a starting point for researchers that can rely on simple questions to shape their choices as they continue to develop an already functional design to have a more in-depth look into some of the other categories or start a new one.

Each tree functions on its own as part of what can be a fully integrated system study that would encompass all the main research foci that compose an RBA study.

Reiterations and conclusions

The success of future off-world colonies depends, at least in part, on safe and sustainable food production. Regolith-based agriculture draws on centuries of humanity’s experience in plant cultivation to make this future possible, while minimizing the costs as well as other challenges associated with the establishment of an off-world colony. Furthermore, RBA leverages the millennia of coevolution between plants and microorganisms to improve nutrient acquisition, reduce stress, and improve disease resistance. However, RBA faces numerous obstacles to implementation ranging from the geological to the biological. Questions and challenges such as which simulants to use and why or the viability of specific plant and/or microbial systems are crucial to the development of bioregenerative life support systems which will be vital to the success of these future missions. From our review of the rich history of regolith biology and geology here in these questions and challenges became clearer and we have summarized them here. These questions are akin to mile markers which must be passed on the road to sustainable plant growth in these challenging environments.

If we extend our analogy just a little, it will be exceedingly difficult to pass these collective mile-markers if we are all traveling on different roads. Indeed, our review also revealed the frequently disparate research and reporting practices within the community of regolith researchers. This is not at all surprising given the varied backgrounds of the community as well as the general lack of any authoritative agency or organization to fund and/or direct research in this area. Our proposed best practices are an attempt to rectify the current lack of oversight and provide a framework for consistent experimentation and reporting of results to accelerate all our research efforts. Finally, it is our sincerest hope that these recommendations will drive new collaborations, provide opportunities for new researchers to make substantiative contributions, and generally improve the connectivity of this community of researchers as we contribute to the development of crucial infrastructure for future off-world colonies.

Schwartzkopf, S. H. Design of a controlled ecological life support system. Bioscience 42 , 526–535 (1992).

Article   CAS   Google Scholar  

Berkovich, Y. A. Evaluation of planting surfaces for crop production in microgravity. Adv. Space Res. 26 , 271–279 (2000).

Article   Google Scholar  

Cooper, M., Douglas, G. & Perchonok, M. Developing the NASA food system for long-duration missions. J. Food Sci. 76 , R40–R48 (2011).

Massa, G., Emmerich, J., Morrow, R., Bourget, C. & Mitchell, C. Plant-growth lighting for space life support: a review. Gravit. Space Biol. Bull. 19 , 19–30 (2006).

Google Scholar  

Perchonok, M. & Bourland, C. NASA food systems: past, present, and future. Nutrition 18 , 913–920 (2002).

Perchonok, M. H., Cooper, M. R. & Catauro, P. M. Mission to Mars: food production and processing for the final frontier. Annu. Rev. Food Sci. Technol. 3 , 311–330 (2012).

Tibbitts, T. W., Wheeler, R. M., Mitchell, C. A. & Heidmann, J. Life sciences: space life support systems and the lunar farside crater Saha proposal. Adv. Space Res. 26 , 245–377 (2000).

Zwart, S. R., Kloeris, V. L., Perchonok, M., Braby, L. & Smith, S. M. Assessment of Nutrient Stability in Foods from the Space Food System After Long‐Duration Spaceflight on the ISS. J. Food Sci. 74 , H209–H217 (2009).

Zabel, P., Bamsey, M., Schubert, D. & Tajmar, M. Review and analysis of over 40 years of space plant growth systems. Life Sci. Space Res. 10 , 1–16 (2016).

Eichler, A. et al. Challenging the agricultural viability of Martian regolith simulants. Icarus 354 , 114022 (2021).

Crites, S. T. & Lucey, P. G. Revised mineral and Mg maps of the Moon from integrating results from the Lunar Prospector neutron and gamma-ray spectrometers with Clementine spectroscopy. Am. Mineral. 100 , 973–982 (2015).

Ehlmann, B. L. & Edwards, C. S. Mineralogy of the Martian surface. Annu. Rev. Earth Planet. Sci. 42 , 291–315 (2014).

Heiken G. H., McKay D. S., and Fruland R. M. Apollo 16 soils – grain size analysis and petrography. In Proc. 4th Lunar Science Conference 251–266 (1973).

Muirhead, B. K., Nicholas, A. K., Umland, J., Sutherland, O. & Vijendran, S. Mars sample return campaign concept status. Acta Astronaut. 176 , 131–138 (2020).

McKay, D. S., et al. Lunar Sourcebook: A User’s Guide to the Moon. The Lunar Regolith (Cambridge University Press, 1991).

McKay, C. P., Imre Friedman, E., Wharton, R. A. & Davies, W. L. History of water on Mars: a biological perspective. Adv. Space Res. 12 , 231–238 (1992).

McSween, H. Y., Jeffrey Taylor, G. & Wyatt, M. B. Elemental composition of the Martian crust. Science 324 , 736–739 (2009).

Chevrier, V. & Mathé, P. E. Mineralogy and evolution of the surface of Mars: a review. Planet. Space Sci. 55 , 289–314 (2007).

Fackrell, L. E., Schroeder, P. A., Thompson, A., Stockstill-Cahill, K. & Hibbitts, C. A. Development of Martian regolith and bedrock simulants: potential and limitations of Martian regolith as an in situ resource. Icarus 354 , 114055 (2021).

Richter, D. D. et al. Soil production and the soil geomorphology legacy of Grove Karl Gilbert. Soil Sci. Soc. Am. J. 84 , 1–20 (2020).

Certini, G. et al. Disambiguating the soils of Mars. Planet. Space Sci. 186 , 104922 (2020).

Duri, L. G. et al. The potential for Lunar and Martian regolith simulants to sustain plant growth: a multidisciplinary overview. Front. Astron. Space Sci. 8 (2022).

Spudis, P. & Pieters, P. Lunar Sourcebook: A User’s Guide to the Moon. Global and Regional Data about the Moon, p. 595–632 (Cambridge University Press, 1991).

Taylor, J. et al. Modal analyses of lunar soils by quantitative X-ray diffraction analysis. Geochim. Cosmochim. Acta 266 , 17–28 (2019).

Ohtake, M. et al. The global distribution of pure anorthosite on the Moon. Nature 461 , 236–240 (2009).

Taylor, G. J., et al. Lunar Sourcebook: A User’s Guide to the Moon. Lunar Rocks . (Cambridge University Press, 1991).

Labotka T. C., Kempa M. J., White C., Papike J. J. & Laul J. C. The lunar regolith: comparative petrology of the Apollo sites. In Proc. 11th Lunar and Planetary Science Conference, 11th, Houston, TX, March 17-21, 1980, Proceedings. Volume 2 (A82-22296 09-91) New York, Pergamon Press, p. 1285-1305. (Vol. 11, pp. 1285-1305).

Simon S. B., Papike J. J. & Laul J. C. The lunar regolith: Comparative studies of the Apollo and Luna sites. In Proc. 12th Lunar and Planetary Science Conference 12th, Houston, TX, March 16-20, 1981, Proceedings. Section 1. (A82-31677 15-91) Vol. 12, pp. 371–388 (New York and Oxford, Pergamon Press, 1982).

Jolliff, B. J., Gillis, J. J., Haskin, L. A., Korotev, R. L. & Wieczorek, M. A. Major lunar crustal terranes: Surface expressions and crust-mantle origins. J. Geophys. Res. Planets 105 , 4197–4216 (2000).

Haskin, L. & Warren, P. Lunar Chemistry. 357–474 (1991).

Pasek, M. A. Phosphorus as a lunar volatile. Icarus 255 , 18–23 (2015).

Taylor, L. A., Pieters, C. M., Keller, L. P., Morris, R. V. & McKay, D. S. Lunar Mare Soils: Space weathering and the major effects of surface-correlated nanophase Fe. J. Geophys. Res. 106 , 985–999 (2001).

Housley, R. M., Grant, R. W., and Paton, N. E. Origin and characteristics of excess Fe metal in lunar glass welded aggregates. Proc. 4th Lunar and Planetary Science Conference , 2737–2749 (1973).

Morris, R. V. The surface exposure (mature) of lunar soils: Some concepts and Is/FeO compilation. In Proc. 9th Lunar and Planetary Science Conference , 9th, Houston, Tex., March 13-17, 1978, Proceedings. Volume 2. (A79-39176 16-91) Vol. 9, pp. 2287–2297 (New York, Pergamon Press, Inc., 1978).

McKay D. S., Morrison D. A., Clanton U. S., Ladle G. H. & Lindsay J. Apollo 12 soil and breccias. In Proc. Second Lunar and Planetary Science Conference , vol. 2, p. 755–774 (1971).

Morris, R. V. Surface exposure indices of lunar soils: a comparative FRM study. In Proc. 7th Lunar and Planetary Science Conference , Houston, Tex., March 15-19, 1976, Proceedings. Volume 1. (A77-34651 15-91), Vol. 7, p. 315–335 (New York, Pergamon Press, Inc., 1976).

Ming, D. W. & Henninger, D. L. Use of lunar regolith as a substrate for plant growth. Adv. Space Res. 14 , 435–443 (1994).

Long-Fox, J., Perman, J., Landsman, Z., Metke, A., and Britt, D. T. Investigating the effects of composition on granular surface area: gas sorption analyses of high-fidelity lunar highlands and carbonaceous chondrite asteroid regolith simulants. In Proc. 53rd Lunar and Planetary Science Conference (2022).

Graf, J. C. Lunar soils grain size catalog. NASA Reference Publication 1265 (1993).

Carrier, D. W., Bromwell, L. G. & Martin, R. T. Strength and compressibility of returned lunar soil. Geochim. Cosmochim. Acta 3 , 3223–3234 (1972).

Mitchell, J. K., Houston, W. N., Carrier, W. D. III & Costes, N. C. Apollo soil mechanics experiment S-200 final report”, NASA Contract NAS 9–11266. Space Sci. Lab. Ser. 15 (University of California, Berkeley, 1974).

Ming, D. W. & Morris, R. V. Chemical, Mineralogical, and Physical Properties of Martian Dust and Soil (Lunar and Planetary Institute, 2017).

Ming, D. W. et al. Geochemical properties of rocks and soils in Gusev Crater, Mars: results of the alpha particle X-ray spectrometer from Cumberland ridge to home plate. J. Geophys. Res. E Planets 113 (2008).

Murchie, S. L. et al. A synthesis of Martian aqueous mineralogy after 1 Mars year of observations from the Mars Reconnaissance Orbiter. J. Geophys. Res. E Planets 114 , 1–30 (2009).

Viviano-Beck, C. E. et al. Revised CRISM spectral parameters and summary products based on the currently detected mineral diversity on Mars. J. Geophys. Res. Planets 119 , 1403–1431 (2014).

Yen, A. S., et al. Evidence for a global Martian soil composition extends to Gale Crater. In Proc. Lunar and Planetary Science Conference , XLIV2013, 44 (2013).

Yen, A. S. et al. An integrated view of the chemistry and mineralogy of martian soils. Nature 436 , 49–54 (2005).

Achilles, C. N. et al. Amorphous phase characterization through X-ray diffraction profile modeling: implications for amorphous phases in gale crater rocks and soils. In Proc. 49th Lunar and Planetary Science Conference p. 2661 (2018).

Achilles, C. N. et al. Mineralogy of an active eolian sediment from the Namib dune, Gale Crater, Mars. J. Geophys. Res. Planets 122 , 2344–2361 (2017).

Bish, D. L. X-ray diffraction results from Mars. Science. 341 , 1–6 (2013).

Blake, D. F. et al. Curiosity at Gale Crater, Mars: characterization and analysis of the rocknest sand shadow. Science 341 , 1239505 (2013).

Rampe, E. B. et al. Mineralogy of an ancient lacustrine mudstone succession from the Murray formation, Gale crater, Mars. Earth Planet. Sci. Lett. 471 , 172–185 (2017).

Rampe, E. B. et al. Mineral trends in early Hesperian lacustrine mudstone at Gale Crater, Mars. In Proc. Lunar and Planetary Science Conference (2017).

Smith, R. J., Rampe, E. B., Horgan, B. H. N. & Dehouck, E. Deriving amorphous component abundance and composition of rocks and sediments on Earth and Mars. J. Geophys. Res. Planets 123 , 2485–2505 (2018).

Dehouck, E., Mclennan, S. M., Sklute, E. C. & Dyar, M. D. Stability and fate of ferrihydrite during episodes of water/rock interactions in early Mars: an experimental approach. J. Geophys. Res. Planets 122 , 358–382 (2017).

Dehouck, E., Mclennan, S. M., Meslin, P.-Y. & Cousin, A. Constraints on abundance, composition, and nature of X-ray amorphous components of soils and rocks at Gale crater, Mars. J. Geophys. Res. Planets 119 , 2640–2657 (2014).

Jeute, T. J., Baker, L. L., Abidin, Z., Bishop, J. L. & Rampe, E. B. Characterizing nanophase materials on Mars: Spectroscopic studies of allophane and imogolite. in Lunar and Planetary Science XLVIII (2017).

Morris, R. V. et al. Chemical composition of crystalline, smectite, and amorphous components for Rocknest soil and John Klein and Cumberland mudstone drill fines using APXS, CheMin, and SAM datasets from Gale Crater Mars. In Proc. 45th Lunar and Planetary Science Conference 1319 (2014).

Squyres, S. W. et al. Detection of silica-rich deposits on Mars. Science 320 , 1063–1067 (2008).

Thompson, A., Rancourt, D. G., Chadwick, O. A. & Jon, C. D. Iron solid-phase differentiation along a redox gradient in basaltic soils. Geochim. Cosmochim. Acta 75 , 119–133 (2011).

Cannon, K. M., Britt, D. T., Smith, T. M., Fritsche, R. F. & Batcheldor, D. Mars global simulant MGS-1: a Rocknest-based open standard for basaltic martian regolith simulants. Icarus 317 , 470–478 (2019).

Fackrell, L. E. Applications of Critical Zone Science in the Exploration of Mars. (University of Georgia, 2021).

Schuerger, A. C., Ming, D. W., Newsom, H. E., Ferl, R. J. & McKay, C. P. Near-term lander experiments for growing plants on Mars: requirements for information on chemical and physical properties of Mars regolith. Life Support Biosphere Sci. 8 , 137–147 (2002).

Wamelink, G. W. W., Frissel, J. Y., Krijnen, W. H. J., Verwoert, M. R. & Goedhart, P. W. Can plants grow on Mars and the Moon: a growth experiment on mars and moon soil simulants. PLOS One. 9 , e103138 (2014).

Hecht, M. H. et al. Detection of perchlorate and the soluble chemistry of Martian soil at the Phoenix Lander Site. Science 325 , 64–67 (2009).

Kounaves, S. P. et al. Identification of the perchlorate parent salts at the Phoenix Mars landing site and possible implications. Icarus 232 , 226–231 (2014).

Toner, J. D., Catling, D. C. & Light, B. Soluble salts at the Phoenix lander site, mars: a reanalysis of the wet chemistry laboratory data. Geochim. Cosmochim. Acta 136 , 142–168 (2014).

Archer, P. D. Jr et al. Abundances and implications of volatile-bearing species from evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars. In Proc. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083) 119 , 2806 (2014).

Kounaves, S. P. et al. Soluble sulfate in the Martian soil at the Phoenix landing site. Geophys. Res. Lett. 37 , 1–5 (2010).

Cull, S. C. et al. Concentrated perchlorate at the Mars Phoenix landing site: evidence for thin film liquid water on Mars. Geophys. Res. Lett . 37 (2010).

Galvin, D. P. Evidence for perchlorates and the origin of chlorinated hydrocarbons detected by SAM at the Rocknest aeolian deposit Gale Crater. J. Geophys. Res. Planets 118 , 1955–1973 (2013).

Hanley, J., Chevrier, V. F., Berget, D. J. & Adams, R. D. Chlorate salts and solutions on Mars. Geophys. Res. Lett . 39 , https://doi.org/10.1029/2012GL051239 (2012).

Visscher, A. M. et al. Growth performance and root transcriptome remodeling of arabidopsis in response to Mars-like levels of magnesium sulfate. PLOS One. 5 , e12348 (2010).

Oze, C. et al. Perchlorate and agriculture on Mars. Soil Syst. 5 , 37 (2021).

Hamissou, M. Selected physiological and molecular responses of Arabidopsis thaliana and Nicotiana tobacum plants irrigated with perhclorate-containing water. Asian J. Plant Sci. 10 , 255–262 (2011).

Calderón, R. et al. A review of perchlorate (ClO4−) occurrence in fruits and vegetables. Environ. Monit. Assess. 189 , 82 (2017).

Davila, A. F., Willson, D., Coates, J. D. & McKay, C. P. Perchlorate on Mars: a chemical hazard and a resource for humans. Int. J. Astrobiology 12 , 321–325 (2013).

Sullivan, R., Anderson, R., Biesiadecki, J., Bond, T. & Stewart, H. Cohesions, friction angles, and other physical properties of Martian regolith from Mars Exploration Rover wheel trenches and wheel scuffs. J. Geophys. Res. E: Planets 116 (2011).

Herkenhoff, K. E. et al. Textures of the soils and rocks at Gusev Crater from Spirit’s microscopic imager. Science 305 , 824–826 (2004).

Spohn, T. et al. The InSight-HP3 mole on Mars: lessons learned from attempts to penetrate to depth in the Martian soil. Adv. Space Res. 69 , 3140–3163 (2022).

Golombek, M. et al. Geology of the InSight landing site on Mars. Nat. Commun. 11 , 1–11 (2020).

Keane, J. T. InSight’s first look inside Mars. Nat. Geosci. 13 , 182 (2020).

McCollom, T. M., Donaldson, C., Moskowitz, B., Berquó, T. S. & Hynek, B. Phosphorous immobility during formation of the layered sulfate deposits of the burns formation at Meridiani Planum. J. Geophys. Res. Planets 123 , 1230–1254 (2018).

Treiman, A. H. et al. Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater). J. Geophys. Res. Planets 121 , 75–106 (2016).

Clauwaert, P. et al. Nitrogen cycling in Bioregenerative Life Support Systems: Challenges for waste refinery and food production processes. Prog. Aerosp. Sci. 91 , 87–98 (2017).

Stern, J. C. et al. Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover investigations at Gale Crater, Mars. Proc. Natl. Acad. Sci. USA 112 , 4245–4250 (2015).

Gasda, P. J. et al. In situ detection of boron by ChemCam on Mars. Geophys. Res. Lett. 44 , 8739–8748 (2017).

Smith, M. L., Claire, M. W., Catling, D. C. & Zahnle, K. J. The formation of sulfate, nitrate and perchlorate salts in the Martian atmosphere. Icarus 231 , 51–64 (2014).

Long-Fox, J. M. and Britt, D. T. Characterization of planetary regolith simulants for the research and development of space resource technologies. Front. Space Technol. 4 , https://doi.org/10.3389/frspt.2023.1255535 (2023).

Long-Fox, J. M., Landsman, Z. A., Easter, P. B., Millwater, C. A. & Britt, D. T. Geomechanical properties of lunar regolith simulants LHS-1 and LMS-1. Adv. Space Res. 71 , 5400–5412 (2023).

Sibille, L., Carpenter, P., Schlagheck, R., French, R. A. Lunar Regolith Simulant Materials: Recommendations for Standardization, Production, and Usage. Marshall Space Flight Center Technical Publication (2006).

Edmunson, J., McLemore, C. A. & Rickman, D. L. Appropriate simulants are a requirement for Mars surface technology. Concepts Approaches Mars Explor. 1679 , 2–3 (2012).

Clark, J. V. et al. JSC-Rocknest: A large-scale Mojave Mars Simulant (MMS) based soil simulant for in situ resource utilization water-extraction studies. Icarus 351 , (2020).

Scott, A. N., Oze, C., Tang, Y. & O’Loughlin, A. Development of a Martian regolith simulant for in situ resource utilization testing. Acta Astronaut. 131 , 45–49 (2017).

Walkinshaw, C. H. & Johnson, P. H. Analysis of vegetable seedlings grown in contact with Apollo 14 lunar surface fines. HortScience 6 , 532–535 (1971).

Walkinshaw, C. H., Sweet, H. C., Venketeswaran, S. & Home, W. H. Results of Apollo 11 and 12 quarantine studies on plants. BioScience 20 , 1297–1302 (1970).

Weete, J. D. & Walkinshaw, C. H. Apollo 12 lunar material: effects on plant pigments. Canad. J. Bot. 50 , 101–104 (1972).

Baur, P. S., Clark, R. S., Walkinshaw, C. H. & Scholes, V. E. Uptake and translocation of elements from Apollo 11 lunar material by lettuce seedlings. Phyton 32 , 133–142 (1974).

CAS   Google Scholar  

Milov, M. & Rusakova, G. Greenhouses in space-higher plants in closed ecological systems. Aviatsia Cosmonaut. 3 , 36–37 (1980).

Walkinshaw, C. H. Space greenhouses could operate efficiently at low pressures if fungi are controlled. Phytopathology 76 , 1141 (1986).

Mashinskiy, A. & Nechitaylo, G. Birth of space agriculture. Tek Molodezhi 4 , 2–7 (1983).

Ming, D. W. & Henninger, D. L. Lunar base agriculture: soils for plant growth. Am. Soc. Agron. 781 , 255 (1989).

Fairchild, K. O., Roberts, B. B. Options for the human settlement of the Moon and Mars. In Ming, D. W. and Henninger, D. L. (Ed.). Lunar Base Agriculture: Soils for Plant Growth. 255 (American Society on Agronomy, 1989).

Aglan, H., Mortley, D., Trotman, A., Loretan, P. & Hill, W. Sweetpotato growth using a microporous tube system with lunar simulant medium. SAE Trans. (JSTOR) 107 , 1012–1016 (1998).

Hossner, L. R., Ming, D. W., Henninger, D. L. & Allen, E. R. Lunar outpost agriculture. Endeavour. 15 , 79–85 (1991).

Walkinshaw, C. H. and Galliano, S. G. New crops for space bases. In: Janick J. and Simon J. E. (eds.) Advances in New Crops. 532–535 (Timber Press, Portland, OR, 1990).

Kozyrovska, N. O. et al. Growing pioneer plants for a lunar base. Adv. Space Res. 37 , 93–99 (2006).

Mortley, D. G., Aglan, H. A., Bonsi, C. K., and Hill, W. A. Growth of Sweetpotato in Lunar and Mars Simulants. SAE. Technical Paper, (No. 2000-01-2289). https://doi.org/10.4271/2000-01-2289 (2000).

Duri, L. G. et al. Mars regolith simulant ameliorated by compost as in situ cultivation substrate improves lettuce growth and nutritional aspects. Plants 9 , 628 (2020).

Wamelink, G. W. W., Frissel, J. Y., Krijnen, W. H. J. & Verwoert, M. R. Crop growth and viability of seeds on Mars and Moon soil simulants. Open Agric. 4 , 509–516 (2019).

Caporale, A. G. et al. Geo-mineralogical characterisation of Mars simulant MMS-1 and appraisal of substrate physico-chemical properties and crop performance obtained with variable green compost amendment rates. Sci. Total Environ. 720 , 137543 (2020).

Misra, G., Smith, W. Garner, M. and Loureiro, R. Potential biological remediation strategies for removing perchlorate from Martian regolith. New Space . 217–227. https://doi.org/10.1089/space.2020.0055 (2021).

Paul, A.-L., Elardo, S. M. & Ferl, R. J. Plants grown in Apollo lunar regolith present stress-associated transcriptomes that inform prospects for lunar exploration. Commun. Biol. 5 , 382 (2022).

Jacoby, R., Peukert, M., Succurro, A., Koprivova, A. & Kopriva, S. The role of soil microorganisms in plant mineral nutrition-current knowledge and future directions. Front. Plant Sci. 8 , 1617 (2017).

Lambers, H., Mougel, C., Jaillard, B. & Hinsinger, P. Plant-microbe-soil interactions in the rhizosphere: an evolutionary perspective. Plant Soil 321 , 83–115 (2009).

Lyu, D., et al. The coevolution of plants and microbes underpins sustainable agriculture. Microorganisms 9 . https://doi.org/10.3390/MICROORGANISMS9051036 (2021).

Morris, J. L. et al. Timescale of early land plant evolution. Proc. Natl Acad. Sci. 115 , E2274–E2283 (2018).

Bulgarelli, D., Schlaeppi, K., Spaepen, S., Van Themaat, E. V. L. & Schulze-Lefert, P. Structure and functions of the bacterial microbiota of plants. Annu. Rev. Plant Biol. 64 , 807–838 (2013).

Egamberdieva, D. et al. High incidence of plant growth-stimulating bacteria associated with the rhizosphere of wheat grown on salinated soil in Uzbekistan. Environ. Microbiol. 10 , 1–9 (2008).

Mendes, R. et al. Deciphering the rhizosphere microbiome for disease-suppressive bacteria. Science 332 , 1097–1100 (2011).

Barea, J. M., Azcón, R. & Azcón-Aguilar, C. Mycorrhizosphere interactions to improve plant fitness and soil quality. Antonie van Leeuwenhoek, Int. J. Gen. Mol. Microbiol. 81 , 343–351 (2002).

Donn, S., Kirkegaard, J. A., Perera, G., Richardson, A. E. & Watt, M. Evolution of bacterial communities in the wheat crop rhizosphere. Environ. Microbiol. 17 , 610–621 (2015).

Dutta, S. & Podile, A. R. Plant Growth Promoting Rhizobacteria (PGPR): the bugs to debug the root zone. Crit. Rev. Microbiol. 36 , 232–244 (2010).

Huang, X.-F. et al. Rhizosphere interactions: root exudates, microbes, and microbial communities. Botany 92 , 267–275 (2014).

Lynch, J. P. Turner review no. 14. Roots of the second green revolution. Aust. J. Bot. 55 , 493–512 (2007).

Mendes, R., Garbeva, P. & Raaijmakers, J. M. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms. FEMS Microbiol. Rev. 37 , 634–663 (2013).

Pingali, P. L. Green revolution: impacts, limits, and the path ahead. Proc. Natl. Acad. Sci. USA 109 , 12302–12308 (2012).

Busby, P. E. et al. Research priorities for harnessing plant microbiomes in sustainable agriculture. PLOS Biol. 15 , e2001793 (2017).

Emmett, B. D., Youngblut, N. D., Buckley, D. H., and Drinkwater, L. E. Plant phylogeny and life history shape rhizosphere bacterial microbiome of summer annuals in an agricultural field. Front. Microbiol . 8 . https://doi.org/10.3389/fmicb.2017.02414 (2017).

Nuccio, E. E. et al. Niche differentiation is spatially and temporally regulated in the rhizosphere. ISME J. 14 , 999–1014 (2020).

Massa, G. D. et al. VEG-01: veggie hardware validation testing on the international space station. Open Agric. 2 , 33–41 (2017).

Schuerger, A. C. et al. Fusarium oxysporum as an opportunistic fungal pathogen on Zinnia hybrida plants grown on Board the International Space Station. Astrobiology 21 , 1029–1048 (2021).

Avila-Herrera, A. et al. Crewmember microbiome may influence microbial composition of ISS habitable surfaces. PLoS One 15 , e0231838 (2020).

Khodadad, C. L. M. et al. Microbiological and nutritional analysis of lettuce crops grown on the International Space Station. Front. Plant Sci. 11 , 199 (2020).

Handy, D. et al. Identification of plant growth promoting bacteria within space crop production systems. Front. Astron. Sp. Sci. 8 , 183 (2021).

Allen, C. C., Griffin, C., Steele, A., Wainwright, N., & Stansbery, E. Microbial life in Martian regolith simulant JSC Mars-1. Lunar and Planetary Science XXXI (2000).

Gutiérrez-Mañero, F. J. et al. The plant-growth-promoting rhizobacteria Bacillus pumilus and Bacillus licheniformis produce high amounts of physiologically active gibberellins. Physiol. Plant. 111 , 206–211 (2001).

Nascimento, F. X., Hernández, A. G., Glick, B. R. & Rossi, M. J. Plant growth-promoting activities and genomic analysis of the stress-resistant Bacillus megaterium STB1, a bacterium of agricultural and biotechnological interest. Biotechnol. Rep. 25 , e00406 (2020).

Coutinho, F. P., Felix, W. P. & Yano-Melo, A. M. Solubilization of phosphates in vitro by Aspergillus spp. and Penicillium spp. Ecol. Eng. 42 , 85–89 (2012).

Yin, Z. et al. Phosphate solubilization and promotion of maize growth by Penicillium oxalicum P4 and Aspergillus niger P85 in a calcareous soil. Can. J. Microbiol. 61 , 913–923 (2015).

Perincherry, L., Lalak-Kánczugowska, J. & Stepién, L. Fusarium-produced mycotoxins in plant-pathogen interactions. Toxins 11 , 664 (2019).

Kral, T. A. & Aitheide, T. S. Methanogen survival following exposure to desiccation, low pressure and martian regolith analogs. Planet. Space Sci. 89 , 167–171 (2013).

Schirmack, J., Alawi, M. & Wagner, D. Influence of Martian regolith analogs on the activity and growth of methanogenic archaea, with special regard to long-term desiccation. Front. Microbiol. 6 , 210 (2015).

Schuerger, A. C., Golden, D. C. & Ming, D. W. Biotoxicity of Mars soils: 1. Dry deposition of analog soils on microbial colonies and survival under Martian conditions. Planet. Space Sci. 72 , 91–101 (2012).

Kerney, K. R. & Schuerger, A. C. Survival of Bacillus subtilis endospores on ultraviolet-irradiated rover wheels and Mars regolith under simulated Martian conditions. Astrobiology 11 , 477–485 (2011).

Cousins, C. R. et al. An ESA roadmap for geobiology in space exploration. Acta Astronaut. 118 , 286–295 (2016).

Volger, R. et al. Mining moon & mars with microbes: biological approaches to extract iron from Lunar and Martian regolith. Planet. Space Sci. 184 , 104850 (2020).

Kaksonen, A. H. et al. Potential of Acidithiobacillus ferrooxidans to grow on and bioleach metals from Mars and Lunar regolith simulants under simulated microgravity conditions. Microorg. 9 , 2416 (2021).

Desbrosses, G. J. & Stougaard, J. Root nodulation: a paradigm for how plant-microbe symbiosis influences host developmental pathways. Cell Host Microbe 10 , 348–358 (2011).

Harris, F., Dobbs, J., Atkins, D., Ippolito, J. A. & Stewart, J. E. Soil fertility interactions with Sinorhizobium-legume symbiosis in a simulated Martian regolith; effects on nitrogen content and plant health. PLoS One 16 , e0257053 (2021).

Rainwater, R. & Mukherjeeid, A. The legume-rhizobia symbiosis can be supported on Mars soil simulants. PLoS One 16 , e0259957 (2021).

Brundrett, M. C. Coevolution of roots and mycorrhizas of land plants. New Phytol. 154 , 275–304 (2002).

Konings-Dudin, G., Butcher, M. J., Castor-Macías, J. A., Kohanloo, B. & Garcia, M. Endomycorrhizal Fungi and Opuntia ficus-indica seed germination on a lunar regolith simulant. Adv. Microbiol. 2014 , 616–626, https://doi.org/10.4236/AIM.2014.410068 (2014).

Gilrain, M. R., Hogan, J. A., Cowan, R. M., Finstein, M. S., and Logendra, L. S. Preliminary study of greenhouse-grown Swiss chard in mixtures of compost and Mars regolith simulant. SAE Tech. Pap . https://doi.org/10.4271/1999-01-2021 (1999).

Zaets, I. et al. Bioaugmentation in growing plants for lunar bases. Advances in Space Research 47 , 1071–1078 (2011).

Lytvynenko, T. et al. A rationally assembled microbial community for growing Tagetes patula L. in a lunar greenhouse. Res. Microbiol. 157 , 87–92 (2006).

Alshaal, T. & El-Ramady, H. Foliar application: from plant nutrition to biofortification. Environ. Biodivers. Soil Secu. 1 , 71–83 (2017).

Clijsters, H. & Van Assche, F. Inhibition of photosynthesis by heavy metals. Photosynth. Res. 7 , 31–40 (1985).

Sharma, B. Responses of Some Vegetable Crops to Toxic Heavy Metals ( Doctoral dissertation) Tribhuvan University (2008).

Badri, D. V. & Vivanco, J. M. Regulation and function of root exudates. Plant Cell Environ. 32 , 666–681 (2009).

Bertin, C., Yang, X. & Weston, L. A. The role of root exudates and allelochemicals in the rhizosphere. Plant Soil 256 , 67–83 (2003).

Keiluweit, M. et al. Mineral protection of soil carbon counteracted by root exudates. Nat. Clim. Change 5 , 588–595 (2015).

Schrader, C. et al. Lunar regolith characterization for simulant design and evaluation using figure of merit algorithms. In 47th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition (p. 755) (2009).

Metzger, P., Britt, D., Covey, S., & Lewis, J. S. Figure of merit for asteroid regolith simulants. In European Planetary Science Congress (Vol. 11) (2017).

Moore, K. & Bradley, L. K. (eds.). North Carolina Extension Gardener Handbook (NC State Extension, College of Agriculture and Life Sciences, NC State University, 2018).

Gavilanes, F. Z. et al. Co-inoculation of Anabaena cylindrica with Azospirillum brasilense increases grain yield of maize hybrids. Rhizosphere 15 , 100224 (2020).

Heydarian, Z. et al. Inoculation of soil with plant growth promoting bacteria producing 1-aminocyclopropane-1-carboxylate deaminase or expression of the corresponding acdS gene in transgenic plants increases salinity tolerance in Camelina sativa. Front. Microbiol. 7 , 1966 (2016).

Kholssi, R., et al. Biofertilizing effects of Anabaena cylindrica biomass on the growth and nitrogen uptake of wheat. 53 , 1216–1225. https://doi.org/10.1080/00103624.2022.2043350 (2022).

Barillot, C. D. C., Sarde, C. O., Bert, V., Tarnaud, E. & Cochet, N. A standardized method for the sampling of rhizosphere and rhizoplan soil bacteria associated to a herbaceous root system. Ann. Microbiol. 632 , 471–476 (2012).

Both, A. J., et al. Guidelines for measuring and reporting environmental parameters for experiments in greenhouses. Plant Methods 11 . https://doi.org/10.1186/s13007-015-0083-5 (2015).

Katagiri, F. et al. Design and construction of an inexpensive homemade plant growth chamber. PLoS One 10 , e0126826 (2015).

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Acknowledgements

The authors thank the NASA Solar System Exploration Research Virtual Institute (SSERVI) Center for Lunar and Asteroid Surface Science (CLASS) (NASA Cooperative Agreement 80NSSSC19M0124), the NASA Space Technology Graduate Research Opportunity (NSTGRO) Fellowship (NASA Cooperative Agreement 80NSSC23K1173), and the Planetary Society for their financial support, which made the publication of this manuscript possible. The authors also acknowledge the Evans Library Open Access Subvention Fund at Florida Tech for assistance with publication costs.

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Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ, 86011, USA

Laura E. Fackrell

Department of Horticultural Science, North Carolina State University, Raleigh, NC, 27607, USA

Samson Humphrey

Department of Biological Sciences, Winston-Salem State University, Winston-Salem, NC, 27101, USA

Rafael Loureiro

Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL, 32904, USA

Andrew G. Palmer

Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, FL, 32904, USA

Department of Physics, University of Central Florida, Orlando, FL, 32816, USA

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Contributions

All authors contributed equally to the manuscript. S.H. and R.L. contributed most greatly to the plant-focused parts of this paper, L.F. contributed most greatly to the regolith properties parts of this paper, especially all the parts that refer to Martian regolith, J.L.F. contributed most greatly to the regolith properties parts of this paper, especially the parts that refer to Lunar regolith, and A.P. contributed most greatly to the parts of this paper that discuss the microbiome. All authors contributed to the graphs, and all authors were heavily involved with editing each others' work. Special thanks to Ralph Fritsche, who reviewed the manuscript and offered his insight before submission.

Corresponding author

Correspondence to Samson Humphrey .

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Fackrell, L.E., Humphrey, S., Loureiro, R. et al. Overview and recommendations for research on plants and microbes in regolith-based agriculture. npj Sustain. Agric. 2 , 15 (2024). https://doi.org/10.1038/s44264-024-00013-5

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DOI : https://doi.org/10.1038/s44264-024-00013-5

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5 5 Experimental design: agricultural field experiments and clinical trials

• Published: August 2011
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This chapter discusses the statistical approach to experimental design, with an emphasis on the core concepts of randomization and blocking. It focuses initially on agricultural field experiments, but also describes the basic elements of a type of medical research investigation known as a clinical trial.

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240+ Experimental Quantitative Research Topics For STEM Students In 2024 (Updated)

STEM stands for Science, Technology, Engineering, and Math, but these are not the only subjects we learn in school. STEM is like a treasure chest of skills that help students become great problem solvers, ready to tackle the real world’s challenges.

In this blog, we are exploring the world of Research Topics for STEM Students. We will explain what STEM really means and why it is so important for students. We will also give you the lowdown on how to pick a fascinating research topic. We will explain a list of 200+ Experimental Quantitative Research Topics For STEM Students.

And when it comes to writing a research title, we will guide you step by step. So, stay with us as we unlock the exciting world of STEM research – it is not just about grades; it is about growing smarter, more confident, and happier along the way.

What Is STEM?

Table of Contents

STEM is Science, Technology, Engineering, and Mathematics. It is a way of talking about things like learning, jobs, and activities related to these four important subjects. Science is about understanding the world around us, technology is about using tools and machines to solve problems, engineering is about designing and building things, and mathematics is about numbers and solving problems with them. STEM helps us explore, discover, and create cool stuff that makes our world better and more exciting.

Why STEM Research Is Important?

STEM research is important because it helps us learn new things about the world and solve problems. When scientists, engineers, and mathematicians study these subjects, they can discover cures for diseases, create new technology that makes life easier, and build things that help us live better. It is like a big puzzle where we put together pieces of knowledge to make our world safer, healthier, and more fun.

• STEM research leads to discoveries and solutions.
• It helps find cures for diseases.
• STEM technology makes life easier.
• Engineers build things that improve our lives.
• Mathematics helps us understand and solve complex problems. There are various Mathematic formulas that students should know.

How to Choose a Topic for STEM Research Paper

Here are some steps to choose a topic for STEM Research Paper:

Step 1: Identify Your Interests

Think about what you like and what excites you in science, technology, engineering, or math. It could be something you learned in school, saw in the news, or experienced in your daily life. Choosing a topic you’re passionate about makes the research process more enjoyable.

Step 2: Research Existing Topics

Look up different STEM research areas online, in books, or at your library. See what scientists and experts are studying. This can give you ideas and help you understand what’s already known in your chosen field.

Step 3: Consider Real-World Problems

Think about the problems you see around you. Are there issues in your community or the world that STEM can help solve? Choosing a topic that addresses a real-world problem can make your research impactful.

Step 4: Talk to Teachers and Mentors

Discuss your interests with your teachers, professors, or mentors. They can offer guidance and suggest topics that align with your skills and goals. They may also provide resources and support for your research.

Step 5: Narrow Down Your Topic

Once you have some ideas, narrow them down to a specific research question or project. Make sure it’s not too broad or too narrow. You want a topic that you can explore in depth within the scope of your research paper.

200+ Experimental Quantitative Research Topics For STEM Students In 2023

Here we will discuss 200+ Experimental Quantitative Research Topics For STEM Students: 

Qualitative Research Topics for STEM Students:

Qualitative research focuses on exploring and understanding phenomena through non-numerical data and subjective experiences. Here are 10 qualitative research topics for STEM students:

• Exploring the experiences of female STEM students in overcoming gender bias in academia.
• Understanding the perceptions of teachers regarding the integration of technology in STEM education.
• Investigating the motivations and challenges of STEM educators in underprivileged schools.
• Exploring the attitudes and beliefs of parents towards STEM education for their children.
• Analyzing the impact of collaborative learning on student engagement in STEM subjects.
• Investigating the experiences of STEM professionals in bridging the gap between academia and industry.
• Understanding the cultural factors influencing STEM career choices among minority students.
• Exploring the role of mentorship in the career development of STEM graduates.
• Analyzing the perceptions of students towards the ethics of emerging STEM technologies like AI and CRISPR. You may check the best AI tools like Top 10 AI Chatbots in 2024: Efficient ChatGPT Alternatives or Rise Of Generative AI: Transforming The Way Businesses Create Content .
• Investigating the emotional well-being and stress levels of STEM students during their academic journey.

Easy Experimental Research Topics for STEM Students:

These experimental research topics are relatively straightforward and suitable for STEM students who are new to research:

• Measuring the effect of different light wavelengths on plant growth.
• Investigating the relationship between exercise and heart rate in various age groups.
• Testing the effectiveness of different insulating materials in conserving heat.
• Examining the impact of pH levels on the rate of chemical reactions.
• Studying the behavior of magnets in different temperature conditions.
• Investigating the effect of different concentrations of a substance on bacterial growth.
• Testing the efficiency of various sunscreen brands in blocking UV radiation.
• Measuring the impact of music genres on concentration and productivity.
• Examining the correlation between the angle of a ramp and the speed of a rolling object.
• Investigating the relationship between the number of blades on a wind turbine and energy output.

Research Topics for STEM Students in the Philippines:

These research topics are tailored for STEM students in the Philippines:

• Assessing the impact of climate change on the biodiversity of coral reefs in the Philippines.
• Studying the potential of indigenous plants in the Philippines for medicinal purposes.
• Investigating the feasibility of harnessing renewable energy sources like solar and wind in rural Filipino communities.
• Analyzing the water quality and pollution levels in major rivers and lakes in the Philippines.
• Exploring sustainable agricultural practices for small-scale farmers in the Philippines.
• Assessing the prevalence and impact of dengue fever outbreaks in urban areas of the Philippines.
• Investigating the challenges and opportunities of STEM education in remote Filipino islands.
• Studying the impact of typhoons and natural disasters on infrastructure resilience in the Philippines.
• Analyzing the genetic diversity of endemic species in the Philippine rainforests.
• Assessing the effectiveness of disaster preparedness programs in Philippine communities.

Read More 

• Frontend Project Ideas
• Business Intelligence Projects For Beginners

Good Research Topics for STEM Students:

These research topics are considered good because they offer interesting avenues for investigation and learning:

• Developing a low-cost and efficient water purification system for rural communities.
• Investigating the potential use of CRISPR-Cas9 for gene therapy in genetic disorders.
• Studying the applications of blockchain technology in securing medical records.
• Analyzing the impact of 3D printing on customized prosthetics for amputees.
• Exploring the use of artificial intelligence in predicting and preventing forest fires.
• Investigating the effects of microplastic pollution on aquatic ecosystems.
• Analyzing the use of drones in monitoring and managing crops.
• Studying the potential of quantum computing in solving complex optimization problems.
• Investigating the development of biodegradable materials for sustainable packaging.
• Exploring the ethical implications of gene editing in humans.

Unique Research Topics for STEM Students:

Unique research topics can provide STEM students with the opportunity to explore unconventional and innovative ideas. Here are 10 unique research topics for STEM students:

• Investigating the use of bioluminescent organisms for sustainable lighting solutions.
• Studying the potential of using spider silk proteins for advanced materials in engineering.
• Exploring the application of quantum entanglement for secure communication in the field of cryptography.
• Analyzing the feasibility of harnessing geothermal energy from underwater volcanoes.
• Investigating the use of CRISPR-Cas12 for rapid and cost-effective disease diagnostics.
• Studying the interaction between artificial intelligence and human creativity in art and music generation.
• Exploring the development of edible packaging materials to reduce plastic waste.
• Investigating the impact of microgravity on cellular behavior and tissue regeneration in space.
• Analyzing the potential of using sound waves to detect and combat invasive species in aquatic ecosystems.
• Studying the use of biotechnology in reviving extinct species, such as the woolly mammoth.

Experimental Research Topics for STEM Students in the Philippines

Research topics for STEM students in the Philippines can address specific regional challenges and opportunities. Here are 10 experimental research topics for STEM students in the Philippines:

• Assessing the effectiveness of locally sourced materials for disaster-resilient housing construction in typhoon-prone areas.
• Investigating the utilization of indigenous plants for natural remedies in Filipino traditional medicine.
• Studying the impact of volcanic soil on crop growth and agriculture in volcanic regions of the Philippines.
• Analyzing the water quality and purification methods in remote island communities.
• Exploring the feasibility of using bamboo as a sustainable construction material in the Philippines.
• Investigating the potential of using solar stills for freshwater production in water-scarce regions.
• Studying the effects of climate change on the migration patterns of bird species in the Philippines.
• Analyzing the growth and sustainability of coral reefs in marine protected areas.
• Investigating the utilization of coconut waste for biofuel production.
• Studying the biodiversity and conservation efforts in the Tubbataha Reefs Natural Park.

Capstone Research Topics for STEM Students in the Philippines:

Capstone research projects are often more comprehensive and can address real-world issues. Here are 10 capstone research topics for STEM students in the Philippines:

• Designing a low-cost and sustainable sanitation system for informal settlements in urban Manila.
• Developing a mobile app for monitoring and reporting natural disasters in the Philippines.
• Assessing the impact of climate change on the availability and quality of drinking water in Philippine cities.
• Designing an efficient traffic management system to address congestion in major Filipino cities.
• Analyzing the health implications of air pollution in densely populated urban areas of the Philippines.
• Developing a renewable energy microgrid for off-grid communities in the archipelago.
• Assessing the feasibility of using unmanned aerial vehicles (drones) for agricultural monitoring in rural Philippines.
• Designing a low-cost and sustainable aquaponics system for urban agriculture.
• Investigating the potential of vertical farming to address food security in densely populated urban areas.
• Developing a disaster-resilient housing prototype suitable for typhoon-prone regions.

Experimental Quantitative Research Topics for STEM Students:

Experimental quantitative research involves the collection and analysis of numerical data to conclude. Here are 10 Experimental Quantitative Research Topics For STEM Students interested in experimental quantitative research:

• Examining the impact of different fertilizers on crop yield in agriculture.
• Investigating the relationship between exercise and heart rate among different age groups.
• Analyzing the effect of varying light intensities on photosynthesis in plants.
• Studying the efficiency of various insulation materials in reducing building heat loss.
• Investigating the relationship between pH levels and the rate of corrosion in metals.
• Analyzing the impact of different concentrations of pollutants on aquatic ecosystems.
• Examining the effectiveness of different antibiotics on bacterial growth.
• Trying to figure out how temperature affects how thick liquids are.
• Finding out if there is a link between the amount of pollution in the air and lung illnesses in cities.
• Analyzing the efficiency of solar panels in converting sunlight into electricity under varying conditions.

Descriptive Research Topics for STEM Students

Descriptive research aims to provide a detailed account or description of a phenomenon. Here are 10 topics for STEM students interested in descriptive research:

• Describing the physical characteristics and behavior of a newly discovered species of marine life.
• Documenting the geological features and formations of a particular region.
• Creating a detailed inventory of plant species in a specific ecosystem.
• Describing the properties and behavior of a new synthetic polymer.
• Documenting the daily weather patterns and climate trends in a particular area.
• Providing a comprehensive analysis of the energy consumption patterns in a city.
• Describing the structural components and functions of a newly developed medical device.
• Documenting the characteristics and usage of traditional construction materials in a region.
• Providing a detailed account of the microbiome in a specific environmental niche.
• Describing the life cycle and behavior of a rare insect species.

Research Topics for STEM Students in the Pandemic:

The COVID-19 pandemic has raised many research opportunities for STEM students. Here are 10 research topics related to pandemics:

• Analyzing the effectiveness of various personal protective equipment (PPE) in preventing the spread of respiratory viruses.
• Studying the impact of lockdown measures on air quality and pollution levels in urban areas.
• Investigating the psychological effects of quarantine and social isolation on mental health.
• Analyzing the genomic variation of the SARS-CoV-2 virus and its implications for vaccine development.
• Studying the efficacy of different disinfection methods on various surfaces.
• Investigating the role of contact tracing apps in tracking & controlling the spread of infectious diseases.
• Analyzing the economic impact of the pandemic on different industries and sectors.
• Studying the effectiveness of remote learning in STEM education during lockdowns.
• Investigating the social disparities in healthcare access during a pandemic.
• Analyzing the ethical considerations surrounding vaccine distribution and prioritization.

Research Topics for STEM Students Middle School

Research topics for middle school STEM students should be engaging and suitable for their age group. Here are 10 research topics:

• Investigating the growth patterns of different types of mold on various food items.
• Studying the negative effects of music on plant growth and development.
• Analyzing the relationship between the shape of a paper airplane and its flight distance.
• Investigating the properties of different materials in making effective insulators for hot and cold beverages.
• Studying the effect of salt on the buoyancy of different objects in water.
• Analyzing the behavior of magnets when exposed to different temperatures.
• Investigating the factors that affect the rate of ice melting in different environments.
• Studying the impact of color on the absorption of heat by various surfaces.
• Analyzing the growth of crystals in different types of solutions.
• Investigating the effectiveness of different natural repellents against common pests like mosquitoes.

Technology Research Topics for STEM Students

Technology is at the forefront of STEM fields. Here are 10 research topics for STEM students interested in technology:

• Developing and optimizing algorithms for autonomous drone navigation in complex environments.
• Exploring the use of blockchain technology for enhancing the security and transparency of supply chains.
• Investigating the applications of virtual reality (VR) and augmented reality (AR) in medical training and surgery simulations.
• Studying the potential of 3D printing for creating personalized prosthetics and orthopedic implants.
• Analyzing the ethical and privacy implications of facial recognition technology in public spaces.
• Investigating the development of quantum computing algorithms for solving complex optimization problems.
• Explaining the use of machine learning and AI in predicting and mitigating the impact of natural disasters.
• Studying the advancement of brain-computer interfaces for assisting individuals with
• disabilities.
• Analyzing the role of wearable technology in monitoring and improving personal health and wellness.
• Investigating the use of robotics in disaster response and search and rescue operations.

Scientific Research Topics for STEM Students

Scientific research encompasses a wide range of topics. Here are 10 research topics for STEM students focusing on scientific exploration:

• Investigating the behavior of subatomic particles in high-energy particle accelerators.
• Studying the ecological impact of invasive species on native ecosystems.
• Analyzing the genetics of antibiotic resistance in bacteria and its implications for healthcare.
• Exploring the physics of gravitational waves and their detection through advanced interferometry.
• Investigating the neurobiology of memory formation and retention in the human brain.
• Studying the biodiversity and adaptation of extremophiles in harsh environments.
• Analyzing the chemistry of deep-sea hydrothermal vents and their potential for life beyond Earth.
• Exploring the properties of superconductors and their applications in technology.
• Investigating the mechanisms of stem cell differentiation for regenerative medicine.
• Studying the dynamics of climate change and its impact on global ecosystems.

Interesting Research Topics for STEM Students:

Engaging and intriguing research topics can foster a passion for STEM. Here are 10 interesting research topics for STEM students:

• Exploring the science behind the formation of auroras and their cultural significance.
• Investigating the mysteries of dark matter and dark energy in the universe.
• Studying the psychology of decision-making in high-pressure situations, such as sports or
• emergencies.
• Analyzing the impact of social media on interpersonal relationships and mental health.
• Exploring the potential for using genetic modification to create disease-resistant crops.
• Investigating the cognitive processes involved in solving complex puzzles and riddles.
• Studying the history and evolution of cryptography and encryption methods.
• Analyzing the physics of time travel and its theoretical possibilities.
• Exploring the role of Artificial Intelligence in creating art and music.
• Investigating the science of happiness and well-being, including factors contributing to life satisfaction.

Practical Research Topics for STEM Students

Practical research often leads to real-world solutions. Here are 10 practical research topics for STEM students:

• Developing an affordable and sustainable water purification system for rural communities.
• Designing a low-cost, energy-efficient home heating and cooling system.
• Investigating strategies for reducing food waste in the supply chain and households.
• Studying the effectiveness of eco-friendly pest control methods in agriculture.
• Analyzing the impact of renewable energy integration on the stability of power grids.
• Developing a smartphone app for early detection of common medical conditions.
• Investigating the feasibility of vertical farming for urban food production.
• Designing a system for recycling and upcycling electronic waste.
• Studying the environmental benefits of green roofs and their potential for urban heat island mitigation.
• Analyzing the efficiency of alternative transportation methods in reducing carbon emissions.

Experimental Research Topics for STEM Students About Plants

Plants offer a rich field for experimental research. Here are 10 experimental research topics about plants for STEM students:

• Investigating the effect of different light wavelengths on plant growth and photosynthesis.
• Studying the impact of various fertilizers and nutrient solutions on crop yield.
• Analyzing the response of plants to different types and concentrations of plant hormones.
• Investigating the role of mycorrhizal in enhancing nutrient uptake in plants.
• Studying the effects of drought stress and water scarcity on plant physiology and adaptation mechanisms.
• Analyzing the influence of soil pH on plant nutrient availability and growth.
• Investigating the chemical signaling and defense mechanisms of plants against herbivores.
• Studying the impact of environmental pollutants on plant health and genetic diversity.
• Analyzing the role of plant secondary metabolites in pharmaceutical and agricultural applications.
• Investigating the interactions between plants and beneficial microorganisms in the rhizosphere.

Qualitative Research Topics for STEM Students in the Philippines

Qualitative research in the Philippines can address local issues and cultural contexts. Here are 10 qualitative research topics for STEM students in the Philippines:

• Exploring indigenous knowledge and practices in sustainable agriculture in Filipino communities.
• Studying the perceptions and experiences of Filipino fishermen in coping with climate change impacts .
• Analyzing the cultural significance and traditional uses of medicinal plants in indigenous Filipino communities.
• Investigating the barriers and facilitators of STEM education access in remote Philippine islands.
• Exploring the role of traditional Filipino architecture in natural disaster resilience.
• Studying the impact of indigenous farming methods on soil conservation and fertility.
• Analyzing the cultural and environmental significance of mangroves in coastal Filipino regions.
• Investigating the knowledge and practices of Filipino healers in treating common ailments.
• Exploring the cultural heritage and conservation efforts of the Ifugao rice terraces.
• Studying the perceptions and practices of Filipino communities in preserving marine biodiversity.

Science Research Topics for STEM Students

Science offers a diverse range of research avenues. Here are 10 science research topics for STEM students:

• Investigating the potential of gene editing techniques like CRISPR-Cas9 in curing genetic diseases.
• Studying the ecological impacts of species reintroduction programs on local ecosystems.
• Analyzing the effects of microplastic pollution on aquatic food webs and ecosystems.
• Investigating the link between air pollution and respiratory health in urban populations.
• Studying the role of epigenetics in the inheritance of acquired traits in organisms.
• Analyzing the physiology and adaptations of extremophiles in extreme environments on Earth.
• Investigating the genetics of longevity and factors influencing human lifespan.
• Studying the behavioral ecology and communication strategies of social insects.
• Analyzing the effects of deforestation on global climate patterns and biodiversity loss.
• Investigating the potential of synthetic biology in creating bioengineered organisms for beneficial applications.

Correlational Research Topics for STEM Students

Correlational research focuses on relationships between variables. Here are 10 correlational research topics for STEM students:

• Analyzing the correlation between dietary habits and the incidence of chronic diseases.
• Studying the relationship between exercise frequency and mental health outcomes.
• Investigating the correlation between socioeconomic status and access to quality healthcare.
• Analyzing the link between social media usage and self-esteem in adolescents.
• Studying the correlation between academic performance and sleep duration among students.
• Investigating the relationship between environmental factors and the prevalence of allergies.
• Analyzing the correlation between technology use and attention span in children.
• Studying how environmental factors are related to the frequency of allergies.
• Investigating the link between parental involvement in education and student achievement.
• Analyzing the correlation between temperature fluctuations and wildlife migration patterns.

Quantitative Research Topics for STEM Students in the Philippines

Quantitative research in the Philippines can address specific regional issues. Here are 10 quantitative research topics for STEM students in the Philippines

• Analyzing the impact of typhoons on coastal erosion rates in the Philippines.
• Studying the quantitative effects of land use change on watershed hydrology in Filipino regions.
• Investigating the quantitative relationship between deforestation and habitat loss for endangered species.
• Analyzing the quantitative patterns of marine biodiversity in Philippine coral reef ecosystems.
• Studying the quantitative assessment of water quality in major Philippine rivers and lakes.
• Investigating the quantitative analysis of renewable energy potential in specific Philippine provinces.
• Analyzing the quantitative impacts of agricultural practices on soil health and fertility.
• Studying the quantitative effectiveness of mangrove restoration in coastal protection in the Philippines.
• Investigating the quantitative evaluation of indigenous agricultural practices for sustainability .
• Analyzing the quantitative patterns of air pollution and its health impacts in urban Filipino areas.

Environmental Science Research Topics for STEM Students In the USA

• Measuring the effect of deforestation on carbon dioxide levels.
• Quantifying the rate of soil erosion under different farming practices.
• Statistical analysis of air pollution levels in urban vs. rural areas.
• Quantifying the impact of plastic pollution on marine life.
• Measuring the efficiency of water purification techniques.
• Statistical comparison of renewable vs. non-renewable energy sources.
• Quantifying the rate of melting glaciers due to global warming.
• Investigating the effect of climate change on species migration patterns.
• Quantitative analysis of the impact of urbanization on local ecosystems.
• Measuring the impact of pesticide use on soil microorganisms.
• Investigating the relationship between water quality and human health.
• Quantifying the impact of conservation efforts on endangered species.
• Statistical analysis of waste generation and recycling rates.
• Measuring the effectiveness of different methods for reducing carbon emissions.
• Quantifying the rate of ocean acidification over time.
• Investigating the effects of oil spills on marine biodiversity.
• Measuring the energy efficiency of different agricultural practices.
• Quantitative study of the relationship between water scarcity and agriculture.
• Investigating the effect of temperature rise on coral reef ecosystems.
• Quantifying the relationship between forest cover and local weather patterns.

Physics Research Topics for STEM Students 

• Measuring the speed of sound in different media.
• Quantifying the energy loss in elastic vs. inelastic collisions.
• Statistical analysis of projectile motion under varying wind conditions.
• The effect of temperature on the resistance of conductors.
• Measuring the impact force in different types of collisions.
• Effects of varying mass on the pendulum oscillation frequency.
• Quantifying the relationship between force, mass, and acceleration.
• Statistical analysis of wave interference patterns in light.
• Measuring the effects of gravitational force on falling objects.
• Analysis of friction’s impact on energy efficiency in different materials.
• Statistical study of voltage drop across different types of resistors.
• Measuring magnetic field strength in different materials.
• The quantitative relationship between electric current and magnetic field generation.
• Effects of varying pressure on gas volume: Boyle’s Law in action.
• Measuring the thermal conductivity of different metals.
• Quantifying energy transfer in different types of heat exchangers.
• The effect of altitude on atmospheric pressure.
• Statistical analysis of the efficiency of different photovoltaic cells.
• Measuring energy conservation in simple harmonic motion.
• Investigating the Doppler effect with different sound frequencies.

Mathematics Research Topics for STEM Students In The USA

• Statistical analysis of correlation coefficients in large data sets.
• Quantifying the probability distribution of random variables in simulations.
• Statistical modeling of population growth trends over time.
• Analyzing the efficiency of different algorithms in solving large datasets.
• A quantitative comparison of different statistical methods for outlier detection.
• Measuring the accuracy of predictive modeling in weather forecasting.
• Application of Monte Carlo methods to model real-world systems.
• Statistical analysis of market trends using regression models.
• Quantitative analysis of game theory in strategic decision making.
• Investigating the effectiveness of machine learning algorithms in pattern recognition.
• Quantifying the chaos theory in weather systems.
• Statistical analysis of the distribution of prime numbers.
• Measuring the complexity of fractal patterns in nature.
• Comparing the efficiency of numerical methods in solving differential equations.
• Quantitative study of optimization algorithms in resource allocation.
• Statistical comparison of geometric vs. arithmetic sequences in population models.
• Quantifying the impact of missing data on statistical model accuracy.
• Measuring the convergence rates of iterative methods in linear algebra.
• Quantitative comparison of algorithms in cryptography.
• Investigating the relationship between network theory and social media dynamics.

Things That Must Keep In Mind While Writing Quantitative Research Title 

Here are a few things that must be kept in mind while writing a quantitative research:

1. Be Clear and Precise

Make sure your research title is clear and says exactly what your study is about. People should easily understand the topic and goals of your research by reading the title.

2. Use Important Words

Include words that are crucial to your research, like the main subjects, who you’re studying, and how you’re doing your research. This helps others find your work and understand what it’s about.

3. Avoid Confusing Words

Stay away from words that might confuse people. Your title should be easy to grasp, even if someone isn’t an expert in your field.

4. Show Your Research Approach

Tell readers what kind of research you did, like experiments or surveys. This gives them a hint about how you conducted your study.

5. Match Your Title with Your Research Questions

Make sure your title matches the questions you’re trying to answer in your research. It should give a sneak peek into what your study is all about and keep you on the right track as you work on it.

Also Read: Exploring Quantitative Biology: A Guide to Research Topics

STEM students, addressing what STEM is and why research matters in this field. It offered an extensive list of research topics , including experimental, qualitative, and regional options, catering to various academic levels and interests. Whether you’re a middle school student or pursuing advanced studies, these topics offer a wealth of ideas. The key takeaway is to choose a topic that resonates with your passion and aligns with your goals, ensuring a successful journey in STEM research. Choose the best Experimental Quantitative Research Topics For STEM students today!

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How to Conduct Research on Your Farm or Ranch

Basics of experimental design.

or call (301) 779-1007 to order.

The previous section summarized the 10 steps for developing and implementing an on-farm research project. In steps 1 through 3, you wrote out your research question and objective, developed a hypothesis, and figured out what you will observe and measure in the field. Now you are ready to actually design the experiment. This section provides more detail on step 4 in the process.

Recall from the introduction that on-farm research provides a way of dealing with the problem of field and environmental variability. In comparing the effects of different practices (treatments), you need to know if the effects that you observe in the crop or in the field are simply a product of the natural variation that occurs in every ecological system, or whether those changes are truly a result of the new practices that you have implemented.

Take the simple example of comparing two varieties of tomatoes: a standard variety and a new one that you have just heard about. You could plant half of a field in the standard variety and the other half of the field in the new variety. You plant the tomatoes on exactly the same day, and you manage both halves of the field exactly the same throughout the growing season. Throughout the harvest period, you keep separate records of the yield from each half of the field so that at the end of the season you have the total yield for each variety. Suppose that under this scenario, the new variety had a 15 percent higher yield than your standard variety. Can you say for sure that the new variety outperforms your standard variety? The answer is no, because there may be other factors that led to the difference in yield, including:

• The new variety was planted in a part of the field that had better soil.
• One end of the field was wetter than the other and some of the tomatoes were infected with powdery mildew.
• Soil texture differences resulted in increased soil moisture from one end of the field to the other.
• Part of the field with the standard variety receives afternoon shade from an adjacent line of trees.
• Weed pressure is greater in one part of the field with the standard variety.
• Adjacent forest or wildlands are a source of pests that affect one end of the field more than the other.

With the right experimental design and statistical analysis, you can identify and isolate the effects of natural variation and determine whether the differences between treatments are “real,” within certain levels of probability. This section looks at three basic experimental design methods: the paired comparison, the randomized complete block and the split-plot design. Which one you choose depends largely on the research question that you are asking and the number of treatments in your experiment (Table 2).

The number of treatments in your experiment should be apparent from your research question and hypothesis. If that is not the case, then you will need to go back and refine your research question so that you have more clarity as to what you are testing. As previously noted, when identifying your research question (step 1), remember to keep things simple. Avoid over-complicating your experiment by trying to do too much at once. And, keep in mind that although the randomized complete block and split-plot designs provide more information than the paired comparison, they also require a larger field area, more management and more sophisticated statistics to analyze the data. Table 2 also lists the type of statistical analysis associated with each experimental design method. These statistical techniques are covered in the next section, Basic Statistical Analysis for On-Farm Research . First is a review of some basic experimental design terminology.

TABLE 2: Three Experimental Design Methods

Treatments: A treatment is the production practice that you are evaluating. Examples of treatments include choice of variety, different fertilizer rates, different fertilizer timing, choice of cover crops, different cover crop management strategies, timing of planting, type of tillage, different pest control methods or different irrigation strategies. For animal operations, treatments might be different feed rations, type of bedding, pasture versus confinement, grazing period, nutritional supplements, or disease/parasite controls. The choices are limitless given the complexity of farming. On-farm research usually compares just two or three practices. In most cases, one of the treatments is the standard practice, or what you usually do, and is known as the “control.”

Small-scale intensive onion production on plastic in Interlaken, NY. Cornell extension vegetable specialist Christine Hoepting found growers could improve yields and reduce bacteria incidence by using alternatives to black plastic mulch, and by increasing planting density. Courtesy Cornell University Cooperative Extension

Variable: In statistics, a variable is any property or characteristic that can be manipulated, measured or counted. In on-farm research, the independent variable is the different treatments (practices) you are applying, and the dependent variable is the effect or outcome you are measuring. What you measure in your particular experiment depends on what treatments you apply. Examples include crop yield, weed density, milk production or animal weight gain.

Plot: Plots are the basic units of a field research project—the specific-sized areas in which each treatment is applied. Replication: Replication means repeating individual treatment plots within the field research area. If you set up an experiment comparing two treatments, instead of setting out just one plot of Treatment A and one plot of Treatment B, you repeat the plots within the field multiple times. Replications reduce experimental error and increase the power of the statistics used to analyze data.

Block: It is usually not possible to find a perfectly uniform field in which to conduct the experiment, and some sources of variation simply cannot be controlled (e.g., slope or soil texture gradients). In order to address the problem of field variability, divide your field of interest into sections that have common slope and soil characteristics. Within each section—typically known as blocks—field conditions should be as uniform as possible. Taken together, however, all of your blocks should encompass the variability that exists across the research area. After delineating the areas for your blocks, make sure you include each treatment inside each block; that way, your blocks can serve as replications. In most on-farm research studies, four to six blocks are sufficient to provide a good level of confidence in the results. Figure 2 provides examples of how to use blocking to address field variability due to slope or soil type.

Agricultural research should usually be blocked because of field variability. If your field has a known gradient, such as a fertility or moisture gradient, it is best to place blocks to that conditions are as uniform as possible within each block. Figure 2a: On a slope, for example, each whole block should occupy about the same elevation. Treatments are randomized and run across the slope within each block. Figure 2b: Place whole blocks within different soil types. Figure 2c: If blocks cannot be used to account for variability, then each treatment should run across the whole gradient, as in all the way down the slope or all the way across the field. This arrangement can also be used for a completely randomized design (see Figure 3).

Randomization: In addition to replication, randomization is also important for addressing the problem of field variability, reducing experimental error and determining the true effect of the treatments you are comparing. Replications should be arranged randomly within the field. Or in the case of a blocked experimental design, treatment plots must be arranged randomly within each block. If you have three treatments, for example, you cannot place those treatments in the same left-to right sequence within each block. They must be arranged in a random order. This can be done using the flip of a coin, drawing numbers from a hat or using a random number generator for each block.

Experimental methods in agriculture

Andrea Onofri and Dario Sacco

Update: v. 1.1 (2023-12-06), compil. 2023-12-13

Introduction

This is the website for the book “Experimental methods in agriculture”, where we deal with the organisation of experiments and data analyses in agriculture and, more generally, in biology. Experiments are the key element to scientific progress and they need to be designed in a way that reliable data is produced. Once this fundamental requirement has been fulfilled, statistics can be used to summarise and explore the results, making a clear distinction between ‘signal’ and ‘noise’ and, hence, reaching appropriate conclusions.

In this book, we will try to give some essential information to support the adoption of good research practices, with particular reference to field experiments, which are used to compare, e.g., innovative genotypes, agronomic practices, herbicides and other weed control methods. We firmly believe that the advancement of cropping techniques should always be based on the evidence provided by scientifically sound experiments.

We will follow a ‘learn-by-doing’ approach, making use of several examples and case studies, while keeping theory and maths at a minimum level; indeed, we are talking to agronomists and biologists and not to statisticians! However, we will not totally remove theory: we think that being able to do some simple hand-calculations is the best way to master the process of data-analysis.

This website is (and will always be) free to use, and is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License. It is written in RMarkdown with the ‘bookdown’ package and it is rebuilt every now and then, to incorporate corrections and updates. This is necessary, as R is a rapidly evolving language.

This book is not written aiming at completeness, but it is finely tuned for a 6 ECTS introductory course in biometry, for master or PhD students. It is mainly aimed at building solid foundations for starting a job in the research field and, eventually, to be able to tackle more advanced statistical material.

How this book is organised

In the first two Chapters we will deal with the experimental design: we need to be able to distinguish good from bad experiments. One key aspect is that our experimental results are only a sample from a universe of possible results and we can never be totally sure that such a sample fully reflects the characteristics of the whole universe. Hence, uncertainty is an unavoidable component of science, which we need to tackle by ensuring that the experimental methods are as reliable as possible.

In Chapter 3 we will show how we can describe the experimental results, based on some simple stats, such as the mean, median, chi square value and Pearson correlation coefficient. In chapter 4 we will introduce some simple models, which we can use to describe the results of our experiments. Of course, the observed data come as the result of deterministic and stochastic processes and, therefore, we will also describe some stochastic models, with particular reference to the Gaussian Density function.

In Chapters 5 and 6 we will talk about statistical inference and Formal Hypothesis Testing. We will describe the basic concepts of confidence intervals, P-levels and error types and we will introduce t-tests and chi-square tests.

From Chapter 7 to Chapter 12 we will talk about the ANOVA, that is one of the most widely used techniques of data analysis. We will show one-way and two-ways ANOVA models and we will also introduce more complex designs, such as the split-plot and strip-plot. Chapter 13 and 14 will be devoted to describe, respectively, linear and nonlinear regression models. In the Chapters from 7 to 14, we will always start from a motivating example, so that the readers can have an idea of the experimental situation, before diving into the details. In the final chapter 15, we will provide exercises for all book chapters, which should help the readers to practice with what they have learned, while reading the book.

Statistical software

In this book, we will work through all the examples by using the R statistical software, together with the RStudio environment. We selected such software for a number of reasons: first of all we like it very much and we think that it is a pleasure to use it, once the initial difficulties have been overcame! Second, it is freeware, which is fundamental for the students. Third, in recent years the software skills of students in master degree or PhD programmes have notably increased and writing small chunks of code is no longer a problem for most of them. Last, but not least, we have seen that some experience with R is a very often required skill when applying for a job. We should acknowledge that R and RStudio are two wonderful pieces of software and we are very much indebted to the whole community who is working to ensure their wide availability and freeware nature.

R is characterised by a modular structure and its basic functionalities can be widely extended by a set of add-in packages. As this is mainly an introductory course, we decided to stick to the main packages, which come with the basic R installation. However, we could not avoid the use of a few very important packages, which we will indicate later on. Of course, it is necessary to state that many of the tasks we perform in this book could be as well (or even better) performed by using additional packages, such as those included in the relatively new ‘tidyverse’ package. We should also mention that this book was built by using the ‘bookdown’ package and it is hosted on the blog ‘www.statforbiology.com’, which is built by using the ‘blogdown’ package. We will not use these two packages during the course, but we should mention that they are really useful.

We will not assume any prior knowledge, and we will start from the very beginning. In order to help the readers, we also provide a very gentle introduction to R as an appendix.

The authors

Andrea is Associate Professor at the Department of Agricultural, Food and Environmental Science, University of Perugia and he has taught ‘Experimental methods in Agriculture’ since 2000. Dario was Associate Professors at the Department of Agricultural, Forest and Food Sciences, University of Torino; he used to teach ‘Experimental Methods in Agriculture’ until 2020, when he suddenly died, far too early. Unfortunately, he could not see this book completed.

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Experimental economics in agriculture: a review of worldwide research.

1. Introduction

2. methodology, 3. results and discussion, 3.1. evolution of the general characteristics of research on experimental economics in agriculture, 3.2. distribution of the research on eea by subject area, type of document, and language, 3.3. most relevant journals in research on eea, 3.4. most relevant countries in terms of research on eea, 3.5. most relevant institutions in the research on eea, 3.6. most relevant authors in research on eea, 3.7. relevant topics in research on eea, 4. conclusions, author contributions, acknowledgments, conflicts of interest.

• Doyon, M.; Rondeau, D.; Mbala, R. Keep It Down: An Experimental Test of the Truncatedk-Double Auction. Agric. Resour. Econ. Rev. 2010 , 39 , 193–212. [ Google Scholar ] [ CrossRef ]
• Smith, V. What is Experimental Economics? Interdisciplinary Center for Economic Science (ICES) at George Mason University: Arlington, TX, USA, 2003. [ Google Scholar ]
• Brañas-Garza, P.; Paz-Espinosa, M. Economía Experimental y del Comportamiento. Pap. Psicólogo 2011 , 32 , 185–193. [ Google Scholar ]
• Birol, E.; Meenakshi, J.V.; Oparinde, A.; Perez, S.; Tomlins, K. Developing country consumers’ acceptance of biofortified foods: A synthesis. Food Secur. 2015 , 7 , 555–568. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Canavari, M.; Drichoutis, A.C.; Lusk, J.L.; Nayga, R.M., Jr. How to run an experimental auction: A review of recent advances. Eur. Rev. Agric. Econ. 2019 , 46 , 862–922. [ Google Scholar ] [ CrossRef ]
• Whitaker, J.B. Whispering in the Ears of Princes—Using Experimental Economics to Evaluate Agricultural and Natural Resource Policies: Discussion. Am. J. Agric. Econ. 2008 , 90 , 1216–1217. [ Google Scholar ] [ CrossRef ]
• Costanigro, M.; Onozaka, Y. A Belief-Preference Model of Choice for Experience and Credence Goods. J. Agric. Econ. 2019 , 71 , 70–95. [ Google Scholar ] [ CrossRef ]
• Marette, S.; Roosen, J.; Blanchemanche, S.; Verger, P. The choice of fish species: An experiment measuring the impact of risk and benefit information. J. Agric. Resour. Econ. 2008 , 33 , 1–18. [ Google Scholar ]
• Galdeano-Gómez, E.; Pérez-Mesa, J.C.; Aznar-Sánchez, J.A. Internationalisation of SMEs and simultaneous strategies of cooperation and competition: An exploratory analysis. J. Bus. Econ. Manag. 2016 , 17 , 1114–1132. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Nguyen, Q.; Leung, P. Do fishermen have different attitudes toward risk? An application of prospect theory to the study of vietnamese fishermen. J. Agric. Resour. Econ. 2009 , 34 , 518–538. [ Google Scholar ]
• Roosen, J.; Marette, S. Making the ‘right’ choice based on experiments: Regulatory decisions for food and health. Eur. Rev. Agric. Econ. 2011 , 38 , 361–381. [ Google Scholar ] [ CrossRef ]
• Disdier, A.-C.; Marette, S. Globalisation issues and consumers’ purchase decisions for food products: Evidence from a laboratory experiment. Eur. Rev. Agric. Econ. 2012 , 40 , 23–44. [ Google Scholar ] [ CrossRef ]
• Hermann, D.; Musshoff, O. Measuring time preferences: Comparing methods and evaluating the magnitude effect. J. Behav. Exp. Econ. 2016 , 65 , 16–26. [ Google Scholar ] [ CrossRef ]
• Garfield, E.; Sher, I.H. New factors in the evaluation of scientific literature through citation indexing. Am. Doc. 1963 , 14 , 195–201. [ Google Scholar ] [ CrossRef ]
• Huang, L.; Zhang, Y.; Guo, Y.; Zhu, D.; Porter, A. Four dimensional Science and Technology planning: A new approach based on bibliometrics and technology roadmapping. Technol. Forecast. Soc. Chang. 2014 , 81 , 39–48. [ Google Scholar ] [ CrossRef ]
• Aznar-Sánchez, J.A.; Velasco-Muñoz, J.F.; López-Felices, B.; Román-Sánchez, I.M. An Analysis of Global Research Trends on Greenhouse Technology: Towards a Sustainable Agriculture. Int. J. Environ. Res. Public Health 2020 , 17 , 664. [ Google Scholar ] [ CrossRef ] [ PubMed ] [ Green Version ]
• Velasco-Muñoz, J.F.; Aznar-Sánchez, J.A.; Batlles-Delafuente, A.; Fidelibus, M.D. Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research. Water 2019 , 11 , 1320. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Santos, J.; Maldonado, M.; Santos, R. Inovação e Conhecimento Organizacional: Um Mapeamento Bibliométrico das Publicações Científicas até 2009. Rev. Organ. Contexto 2011 , 7 , 31–58. [ Google Scholar ] [ CrossRef ]
• Albort-Morant, G.; Henseler, J.; Leal-Millán, A.; Cepeda-Carrión, G. Mapping the Field: A Bibliometric Analysis of Green Innovation. Sustainability 2017 , 9 , 1011. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Robinson, D.K.; Huang, L.; Guo, Y.; Porter, A. Forecasting Innovation Pathways (FIP) for new and emerging science and technologies. Technol. Forecast. Soc. Chang. 2013 , 80 , 267–285. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Galvez, C. Análisis de co-palabras aplicado a los artículos muy citados en Biblioteconomía y Ciencias de la Información (2007–2017). Transinformação 2018 , 30 , 277–286. [ Google Scholar ] [ CrossRef ]
• Durieux, V.; Gevenois, P.A. Bibliometric Indicators: Quality Measurements of Scientific Publication. Radiology 2010 , 255 , 342–351. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Li, W.; Zhao, Y. Bibliometric analysis of global environmental assessment research in a 20-year period. Environ. Impact Assess. Rev. 2015 , 50 , 158–166. [ Google Scholar ] [ CrossRef ]
• Mongeon, P.; Paul-Hus, A. The journal coverage of Web of Science and Scopus: A comparative analysis. Science 2015 , 106 , 213–228. [ Google Scholar ] [ CrossRef ]
• Gavel, Y.; Iselid, L. Web of Science and Scopus: A journal title overlap study. Online Inf. Rev. 2008 , 32 , 8–21. [ Google Scholar ] [ CrossRef ]
• Aznar-Sánchez, J.A.; Belmonte-Ureña, L.J.; Velasco-Muñoz, J.F.; Manzano-Agugliaro, F. Economic analysis of sustainable water use: A review of worldwide research. J. Clean. Prod. 2018 , 198 , 1120–1132. [ Google Scholar ] [ CrossRef ]
• Aznar-Sánchez, J.A.; Piquer-Rodríguez, M.; Velasco-Muñoz, J.F.; Manzano-Agugliaro, F. Worldwide research trends on sustainable land use in agriculture. Land Use Policy 2019 , 87 , 104069. [ Google Scholar ] [ CrossRef ]
• Aznar-Sánchez, J.A.; Velasco-Muñoz, J.F.; Belmonte-Ureña, L.J.; Manzano-Agugliaro, F. Innovation and technology for sustainable mining activity: A worldwide research assessment. J. Clean. Prod. 2019 , 221 , 38–54. [ Google Scholar ] [ CrossRef ]
• Cascajares, M.; Alcayde, A.; Salmerón-Manzano, E.; Manzano-Agugliaro, F. Transfer of Agricultural and Biological Sciences Research to Patents: The Case of EU-27. Agronomy 2021 , 11 , 252. [ Google Scholar ] [ CrossRef ]
• Bonilla, C.A.; Merigó, J.M.; Torres-Abad, C. Economics in Latin America: A bibliometric analysis. Science 2015 , 105 , 1239–1252. [ Google Scholar ] [ CrossRef ]
• Stenger, A. Experimental valuation of food safety: Application to sewage sludge. Food Pol. 2000 , 25 , 211–218. [ Google Scholar ] [ CrossRef ]
• Lusk, J.L.; Fox, J.A.; Schroeder, T.C.; Mintert, J.; Koohmaraie, M. In-store valuation of steak tenderness. Am. J. Agric. Econ. 2001 , 83 , 539–550. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Toler, S.; Briggeman, B.C.; Lusk, J.L.; Adams, D.C. Fairness, farmers markets, and local production. Am. J. Agric. Econ. 2009 , 91 , 1272–1278. [ Google Scholar ] [ CrossRef ]
• Bieberstein, A.; Roosen, J.; Marette, S.; Blanchemanche, S.; Vandermoere, F. Consumer choices for nano-food and nano-packaging in France and Germany. Eur. Rev. Agric. Econ. 2012 , 40 , 73–94. [ Google Scholar ] [ CrossRef ]
• Lusk, J.L.; Coble, K.H. Risk perceptions, risk preference, and acceptance of risky food. Am. J. Agric. Econ. 2005 , 87 , 393–405. [ Google Scholar ] [ CrossRef ]
• de Koeijer, T.; Wossink, G.; Smit, A.; Janssens, S.; Renkema, J.; Struik, P. Assessment of the quality of farmers’ environmental management and its effects on resource use efficiency: A Dutch case study. Agric. Syst. 2003 , 78 , 85–103. [ Google Scholar ] [ CrossRef ]
• Messer, K.D.; Schmit, T.M.; Kaiser, H.M. Optimal Institutional Mechanisms for Funding Generic Advertising: An Experimental Analysis. Am. J. Agric. Econ. 2005 , 87 , 1046–1060. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Musshoff, O.; Odening, M.; Schade, C.; Maart-Noelck, S.C.; Sandri, S. Inertia in disinvestment decisions: Experimental evidence. Eur. Rev. Agric. Econ. 2012 , 40 , 463–485. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Maart-Noelck, S.C.; Musshoff, O. Investing Today or Tomorrow? An Experimental Approach to Farmers’ Decision Behaviour. J. Agric. Econ. 2012 , 64 , 295–318. [ Google Scholar ] [ CrossRef ]
• Warnick, J.C.E.; Escobal, J.; Laszlo, S.C. Ambiguity Aversion and Portfolio Choice in Small-Scale Peruvian Farming. BE J. Econ. Anal. Policy 2011 , 11 , 1–56. [ Google Scholar ] [ CrossRef ]
• Bocquého, G.; Jacquet, F.; Reynaud, A. Expected utility or prospect theory maximisers? Assessing farmers’ risk behaviour from field-experiment data. Eur. Rev. Agric. Econ. 2013 , 41 , 135–172. [ Google Scholar ] [ CrossRef ]
• Brunette, M.; Foncel, J.; Kéré, E.N. Attitude towards Risk and Production Decision: An Empirical Analysis on French Private Forest Owners. Environ. Model. Assess. 2017 , 22 , 563–576. [ Google Scholar ] [ CrossRef ]
• Gars, J.; Ward, P.S. Can differences in individual learning explain patterns of technology adoption? Evidence on heterogeneous learning patterns and hybrid rice adoption in Bihar, India. World Dev. 2019 , 115 , 178–189. [ Google Scholar ] [ CrossRef ]
• Pollard, C.R.J.; Redpath, S.; Bussière, L.F.; Keane, A.; Thompson, D.B.A.; Young, J.C.; Bunnefeld, N. The impact of uncertainty on cooperation intent in a conservation conflict. J. Appl. Ecol. 2019 , 56 , 1278–1288. [ Google Scholar ] [ CrossRef ]
• Senapati, A.K. Evaluation of risk preferences and coping strategies to manage with various agricultural risks: Evidence from India. Heliyon 2020 , 6 , e03503. [ Google Scholar ] [ CrossRef ]
• Wu, S.; Roe, B. Behavioral and Welfare Effects of Tournaments and Fixed Performance Contracts: Some Experimental Evidence. Am. J. Agric. Econ. 2005 , 87 , 130–146. [ Google Scholar ] [ CrossRef ]
• Yesuf, M.; Bluffstone, R.A. Poverty, risk aversion, and path dependence in low-income countries: Experimental evidence from Ethiopia. Am. J. Agric. Econ. 2009 , 91 , 1022–1037. [ Google Scholar ] [ CrossRef ]
• Kanter, C.; Messer, K.D.; Kaiser, H.M. Does Production Labeling Stigmatize Conventional Milk? Am. J. Agric. Econ. 2009 , 91 , 1097–1109. [ Google Scholar ] [ CrossRef ]
• Dillaway, R.; Messer, K.D.; Bernard, J.C.; Kaiser, H.M. Do consumer responses to media food safety information last? Appl. Econ. Perspect. Policy 2011 , 33 , 363–383. [ Google Scholar ] [ CrossRef ]
• Wu, S.; Fooks, J.R.; Messer, K.D.; Delaney, D. Consumer demand for local honey. Appl. Econ. 2015 , 47 , 4377–4394. [ Google Scholar ] [ CrossRef ]
• Palm-Forster, L.H.; Ferraro, P.J.; Janusch, N.; Vossler, C.A.; Messer, K.D. Behavioral and Experimental Agri-Environmental Research: Methodological Challenges, Literature Gaps, and Recommendations. Environ. Resour. Econ. 2019 , 73 , 719–742. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Murphy, J.J.; Stevens, T.H. Contingent valuation, hypothetical bias, and experimental economics. Agric. Res. Econ. Rev. 2004 , 33 , 182–192. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Poe, G.L.; Schulze, W.D.; Segerson, K.; Suter, J.F.; Vossler, C.A. Exploring the Performance of Ambient-Based Policy Instruments When Nonpoint Source Polluters Can Cooperate. Am. J. Agric. Econ. 2004 , 86 , 1203–1210. [ Google Scholar ] [ CrossRef ]
• Lybbert, T.J. Indian farmers’ valuation of yield distributions: Will poor farmers value ‘pro-poor’ seeds? Food Pol. 2006 , 31 , 415–441. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Bougherara, D.; Combris, P. Eco-labelled food products: What are consumers paying for? Eur. Rev. Agric. Econ. 2009 , 36 , 321–341. [ Google Scholar ] [ CrossRef ]
• Cecchini, L.; Torquati, B.; Chiorri, M. Sustainable agri-food products: A review of consumer preference studies through experimental economics. Agric. Econ. 2018 , 64 , 554–565. [ Google Scholar ] [ CrossRef ]
• Chang, J.B.; Lusk, J.L.; Norwood, F.B. How Closely Do Hypothetical Surveys and Laboratory Experiments Predict Field Behavior? Am. J. Agric. Econ. 2009 , 91 , 518–534. [ Google Scholar ] [ CrossRef ]
• Lusk, J.L.; Norwood, F.B. Speciesism, altruism and the economics of animal welfare. Eur. Rev. Agric. Econ. 2011 , 39 , 189–212. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Abbink, K.; Moller, L.C.; O’Hara, S. Sources of Mistrust: An Experimental Case Study of a Central Asian Water Conflict. Environ. Resour. Econ. 2009 , 45 , 283–318. [ Google Scholar ] [ CrossRef ]

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Mesa-Vázquez, E.; Velasco-Muñoz, J.F.; Aznar-Sánchez, J.A.; López-Felices, B. Experimental Economics in Agriculture: A Review of Worldwide Research. Agronomy 2021 , 11 , 1566. https://doi.org/10.3390/agronomy11081566

Mesa-Vázquez E, Velasco-Muñoz JF, Aznar-Sánchez JA, López-Felices B. Experimental Economics in Agriculture: A Review of Worldwide Research. Agronomy . 2021; 11(8):1566. https://doi.org/10.3390/agronomy11081566

Mesa-Vázquez, Ernesto, Juan F. Velasco-Muñoz, José A. Aznar-Sánchez, and Belén López-Felices. 2021. "Experimental Economics in Agriculture: A Review of Worldwide Research" Agronomy 11, no. 8: 1566. https://doi.org/10.3390/agronomy11081566

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45 Research Project Ideas in Agriculture – Innovative Approaches to Sustainable Farming

Explore 45 research project ideas in agriculture for sustainable farming.

Agriculture is a vast and dynamic field that plays a critical role in feeding the world’s population. As the global population continues to grow, the demand for food production is also increasing, making agriculture one of the most important sectors for ensuring food security and sustainable development. However, the challenges facing the agriculture industry today are numerous, ranging from climate change, soil degradation, water scarcity, and pest infestation to biodiversity loss and food waste.

To tackle these issues and promote sustainable agriculture, researchers and professionals in the field are continuously exploring new and innovative ways to improve agricultural practices, increase productivity, and reduce environmental impact. In this article, we will present 45 research project ideas in agriculture that can help address some of the most pressing issues facing the industry today.

These research projects cover a wide range of topics, from soil health and crop yields to livestock farming, aquaculture, and food systems, providing a comprehensive overview of the latest trends and innovations in agricultural research.

Whether you are a student, researcher, or professional in the field, these research project ideas can help guide your work and contribute to a more sustainable and resilient agriculture industry.

• Evaluating the effectiveness of natural pest control methods in agriculture.
• Investigating the effects of climate change on crop yields and food security.
• Studying the impact of soil quality on plant growth and crop yields.
• Analyzing the potential of precision agriculture techniques to increase yields and reduce costs.
• Assessing the feasibility of vertical farming as a sustainable solution to food production.
• Investigating the impact of sustainable agriculture practices on soil health and ecosystem services.
• Exploring the potential of agroforestry to improve soil fertility and crop yields.
• Developing strategies to mitigate the effects of drought on crop production.
• Analyzing the impact of irrigation management techniques on crop yields and water use efficiency.
• Studying the potential of biochar as a soil amendment to improve crop productivity.
• Investigating the effects of soil compaction on crop yields and soil health.
• Evaluating the impact of soil erosion on agriculture and ecosystem services.
• Developing integrated pest management strategies for organic agriculture.
• Assessing the potential of cover crops to improve soil health and reduce erosion.
• Studying the effects of biofertilizers on crop yields and soil health.
• Investigating the potential of phytoremediation to mitigate soil pollution in agriculture.
• Developing sustainable practices for livestock farming and manure management.
• Studying the effects of climate change on animal health and productivity.
• Analyzing the impact of animal feeding practices on meat quality and safety.
• Investigating the potential of aquaponics to increase food production and reduce environmental impact.
• Developing strategies to reduce food waste and loss in agriculture.
• Studying the effects of nutrient management practices on crop yields and environmental impact.
• Evaluating the potential of organic agriculture to improve soil health and reduce environmental impact.
• Investigating the effects of land use change on agriculture and biodiversity.
• Developing strategies to reduce greenhouse gas emissions from agriculture.
• Analyzing the impact of agricultural policies on food security and sustainability.
• Studying the potential of precision livestock farming to improve animal welfare and productivity.
• Investigating the impact of agrochemicals on soil health and biodiversity.
• Developing sustainable practices for fisheries and aquaculture.
• Studying the potential of bioremediation to mitigate pollution in aquaculture.
• Investigating the effects of climate change on fisheries and aquaculture.
• Developing strategies to reduce water pollution from agriculture and aquaculture.
• Studying the impact of land use change on water resources and aquatic ecosystems.
• Evaluating the potential of agroecology to promote sustainable agriculture and food systems.
• Investigating the impact of climate-smart agriculture practices on food security and resilience.
• Studying the potential of agrobiodiversity to improve crop productivity and resilience.
• Analyzing the impact of agricultural trade on food security and sustainability.
• Investigating the effects of urbanization on agriculture and food systems.
• Developing strategies to promote gender equity in agriculture and food systems.
• Studying the potential of agroforestry to promote biodiversity and ecosystem services.
• Analyzing the impact of food systems on public health and nutrition.
• Investigating the effects of climate change on pollination and crop yields.
• Developing strategies to promote agrotourism and rural development.
• Studying the potential of agroforestry to promote carbon sequestration and mitigate climate change.
• Analyzing the impact of agricultural subsidies on food security and sustainability.

I hope this article would help you to know the new project topics and research ideas in Agricultural.

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• food systems
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• soil health
• sustainable farming

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187 Agriculture Essay Topics & Research Questions + Examples

Are you looking for the best agriculture topics to write about? You’re at the right place! StudyCorgi has prepared a list of important agriculture research topics. On this page, any student can find essay questions and project ideas on various agricultural issues, such as food safety, genetically engineered crops, and sustainable farming practices.

👨‍🌾 TOP 7 Agriculture Research Topics – 2024

🏆 best essay topics on agriculture, 🎓 most interesting agriculture topics for college students, 👍 good agriculture research topics & essay examples, 💡 cool agricultural research topics for high school students, ❓ research questions about agriculture, 🔎 current agriculture research paper topics, 📝 agriculture argumentative essay topics, 🗣️ agriculture topics for speech.

• Agriculture and Its Role in Economic Development
• Commercial Agriculture, Its Role and Definition
• Agriculture: Personal Field Visit
• Food Safety Issues in Modern Agriculture
• Globalization Impact on Sustainable Agriculture
• Agricultural Biotechnology and Its Pros and Cons
• Improving Stress Resistance in Agricultural Crops
• In Support of Robotics Use in Agriculture Robotic technologies have vast potential to be used in the agricultural sector due to the multi-dimensional nature of their applications and the possibilities for ongoing improvement.
• Soil: The Essential Aspect of Agriculture Soil is an integral part of human life as it determines one’s quality of life. The health of the soil is reduced by erosion and degradation due to human activities.
• Agricultural Influences on the Developing Civil Society Agriculture had a significant influence on developing societies, ranging from creating trade to bringing industrialization, education, and social classes.
• History of Agricultural Technology Development Agricultural technologies were majorly developed during the Medieval period to ensure sufficient product yields for growing populations around the world.
• Population Growth and Agriculture in the Future The current industrial agriculture needs to be advanced and developed in combination with sustainable agricultural practices.
• Industry and Agriculture: Use of Technology Industry and agriculture are among the areas that have experienced a vast rise in effectiveness and performance quality due to the integration of new types of technology into them.
• Pedagogical Content Knowledge in Secondary Level Agricultural Science Apart from internal student factors, such as the ability to generalize and absorb new knowledge, the learning process is significantly affected by the teacher.
• Agriculture and Food in Ancient Greece The paper states that agricultural practices and goods from Greece extended to neighboring countries in the Mediterranean as the dominance increased.
• Hunting and Gathering Versus Agricultural Society The hunting and gathering society is considered the most equitable of all seven types, while the agricultural community gives rise to the development of civilization.
• The Agriculture Industry’s Digital Transformation This study seeks to explore the dynamics of digital technology in agriculture over the past two decades, focusing on the perspectives and perceptions of the farmers.
• Aspects of Pesticide Use in Agriculture This paper investigates socio-environmental factors connected with pesticide use in agriculture and food production. It has a destructive impact on the environment
• Food and Agriculture of Ancient Greece The concepts of agriculture and cuisine both have a deep connection to Greek history, culture, development, and social trends.
• Sustainable Agriculture Against Food Insecurity The paper argues sustainable agriculture is one way to reduce food insecurity without harming the planet because the number of resources is currently decreasing.
• Agriculture in Honduras: Existing Challenges and Possible Solutions This paper tackles the issue of existing challenges and possible solutions to the problems of agriculture in Honduras.
• Freedom in American Countryside and Agriculture This paper portrays how freedom has been eliminated in the countryside by the state agriculture department, and whether the farmer has a moral right to do his farming practices.
• The Impact of Pesticides’ Use on Agriculture Pesticides are mostly known for their adverse effects and, therefore, have a mostly negative connotation when discussed among general audiences.
• Agriculture Development and Related Theories There are two main domestication models used to describe the development of agriculture: unconscious and conscious.
• Agricultural Technology Implementation by Medieval Europeans and West Africans The paper examines how West Africans and Medieval Europeans were affected by their corresponding climates and why their methods were unique to their respective locations.
• Agriculture: Application of Information Technology IT application in agriculture has contributed to food security in most modern communities. Farming has become easier than before as new inventions are made.
• European Invasion and Agriculture in the Caribbean The early invasion of the Europeans in the Caribbean did not prompt the employment of the slave trade in the agricultural activities until the development of the sugar plantations.
• Governmental Price Control in Agricultural Sector The consequences of real-life governmental price control are the evolutionary nature of transformations in the agricultural sector.
• Trade Peculiarities in Food and Agriculture Food trading is a peculiar area, as food is the basis for surviving the population. The one who controls food production and trading routes, also controls all populations.
• Climate Changes Impact on Agriculture and Livestock The project evaluates the influences of climate changes on agriculture and livestock in different areas in the Kingdom of Saudi Arabia.
• Agricultural Problems in Venezuela Agriculture has been greatly underdeveloped in Venezuela, yet it is a country that has vital minerals and resources required for the global economy.
• Market Revolution: Agriculture and Global Trade In the era of traders, the vast land area and rich natural resources created many economic opportunities. Most people lived in rural areas and were engaged in agriculture.
• Repeasantization: Impact on Agriculture The repeasantization led to fundamental changes that created a new system of agriculture that is still relevant today.
• Agriculture, Water, and Food Security in Tanzania This paper evaluates the strategies applicable to the development and further maintenance of agriculture, water, and food security in Tanzania.
• The Australian Agriculture Company’s Financial Analysis The Australian Agriculture Company shows a positive sign for investment due to its financial analysis indicating company resilience and strong prospects of growth.
• Agriculture and Food Production in the Old Kingdom
• Agriculture and the Transition to the Market in Asia
• Agrarian Reform and Subsistence Agriculture in Russia
• Agriculture, Nutrition, and the Green Revolution in Bangladesh
• Agriculture Business and Management
• Agriculture, Horticulture, and Ancient Egypt
• Agriculture and Food Production in the Old Kingdom of Egypt
• Administrative and Transaction-Related Costs of Subsidising Agriculture
• Agriculture and Economic Growth in Argentina, 1913-84
• Agriculture and Economic Development in Brazil, 1960-1995
• Agriculture and Greenhouse Gas Cap-And-Trade
• Croatian Agriculture Towards World Market Liberalization
• Adapting Credit Risk Models to Agriculture
• Agriculture and European Union Enlargement
• Agriculture and Food Security in Pakistan
• Cash Flows and Financing in Texas Agriculture
• Current Problems With Indian Agriculture
• Agriculture and Its Drain on California
• Agriculture and the Economic Life of India
• Agriculture and Global Climate Stabilization
• Achieving Regional Growth Dynamics in African Agriculture
• Agriculture and Non-agricultural Liberalization in the Millennium Round
• Corporate Agriculture and Modern Times
• Agriculture and Rural Employment Agricultural in Bolivia
• Climatic Fluctuations and the DI¤Usion of Agriculture
• Agriculture Global Market Briefing
• Agriculture and the Industrial Revolution of the Late 1700s
• Agriculture and Animal Husbandry in Ecuador
• Biofuels, Agriculture, and Climate Change
• Aggregate Technical Efficiency and Water Use in U.S. Agriculture
• Agriculture-Led Food Crops and Cash Crops in Tanzania This paper aims to explore the contributions of the agriculture sector in Tanzania to the country’s industrialization process by using recent data about its food and cash crops.
• Cuisine and Agriculture of Ancient Greece There are many reasons for modern students to investigate the development of cuisine and agriculture in Ancient Greece.
• Agriculture and Food Safety in the United States Agriculture in the United States has grown progressively centralized. The shortcomings in the 2018 U.S. farm legislation resulted in multiple challenges in the food system.
• Sustainable Agriculture and Future Perspectives Sustainable agriculture is essential to the earth’s environment. When farmers take care of their land and crops, they are taking care of environmental sustainability.
• Colonialism and Economic Development of Africa Through Agriculture The colonial period is characterized by the exploitation of the agricultural sector in Africa to make a profit and provide Western countries with raw materials.
• Agricultural Adaptation to Changing Environments The paper discusses the impact of climate change on agriculture in Canada. This phenomenon is real and has affected the industry over at least the last three decades.
• The Neolithic Era: Architecture and Agriculture The improvements to agriculture, society, architecture, and culture made during the Neolithic period had an undeniable impact on aspects of the world.
• The Big History of Civilizations – Origins of Agriculture: Video Analysis This paper aims to analyze the origins of agriculture – what was a foraging economy and way of life like, as well as compare foragers and farmers.
• Impacts of Climate Change on Agriculture and Food This paper will examine four aspects of climate change: variation in the rainfall pattern, water levels, drought, temperature, and heatwaves.
• Agricultural Traditions of Canadians In Canada there is a very good agricultural education, so young people can get higher education in agriculture and use it on their own farms.
• Sharecropping. History of Racial Agriculture Sharecropping became a variation of racialized agriculture, that which has negative impact on the capabilities of the black population to generate and pass down wealth.
• Food Additives Use in Agriculture in the United States Food additives in agriculture become a debatable issue because their benefits do not always prevail over such shortages like health issues and environmental concerns.
• Radio-Frequency Identification in Healthcare and Agriculture Specifically, radio-frequency identification (RFID) has gained traction due to its ability to transmit data over distance.
• Mechanism of US Agricultural Market The fact that lower interest rates increased the number of potential customers for real estate in the 2000s shows that housing prices should have increased.
• A Biological Terror Attack in Agriculture The United States is highly vulnerable to terror attacks of biological nature in agriculture yet such an occurrence can cripple the economy.
• The Economics of Race, Agriculture and Environment This research paper is going to answer the question; do public policies reduce or enhance racial inequality in agricultural and environmental affairs?
• Agriculture the Backbone of Ancient Egypt’s Economy In pre-industrial societies, agriculture was the backbone of most economies. This is true in ancient times and very much evident in ancient Egypt.
• Impact of Bioterrorism on the U.S Agriculture System The paper describes that the term bioterrorism has several definitions depending upon the origin of the attack but in general terms, it refers to any form of terrorist attack.
• Impacts of Genetic Engineering of Agricultural Crops In present days the importance of genetic engineering grew due to the innovations in biotechnologies and Sciences.
• The Effects of Genetic Modification of Agricultural Products Discussion of the threat to the health of the global population of genetically modified food in the works of Such authors as Jane Brody and David Ehrenfeld.
• Climate Change and Its Potential Impact on Agriculture and Food Supply The global food supply chain has been greatly affected by the impact of global climate change. There are, however, benefits as well as drawbacks to crop production.
• Agriculture and Mayan Society Resilience The Yucatan peninsula had a vast landscape which was good for agriculture thus making agriculture to be the main economic base for the Mayans.
• Homeland Security in Agriculture and Health Sectors Lack of attention to the security and protection of the agricultural sector in the U.S. economy can create a serious threat to the health and safety of the population.
• Water Savings and Virtual Trade in Agriculture Water trade in agriculture is not a practice that is unique to the modern generation. The practice was common long before the emergence of the Egyptian Empire.
• Virtual Water Trade and Savings in Agriculture This essay discusses the savings associated with virtual water trade in agriculture and touches on the effects of a shift to local agricultural production on global water savings.
• Virtual Water Trade of Agricultural Products Virtual water trade is a concept associated with globalization and the global economy. Its rise was motivated by growing water scarcity in arid areas around the world.
• Agricultural Role in African Development Diao et al. attempt to determine the role of agriculture in overcoming the challenge of poverty in rural areas of Africa compared to alternative theories of economic growth.
• Virtual Water Savings and Trade in Agriculture The idea of virtual water was initially created as a method for assessing how water-rare nations could offer food, clothing, and other water-intensive products to their residents.
• According to Henretta & Brody, Gang System Revolutionized Agriculture This paper analyzes America’s contribution in prevention of natural calamities, decline of soil quality, promotion of production outlay and provision of sufficient food.
• Capital Taxes and Agriculture
• Canadian Trade With the Chinese Agriculture Market
• Agriculture and Its Impact on Economic Development
• Bacteriocins From the Rhizosphere Microbiome From an Agriculture Perspective
• Agriculture and Its Impact on Financial Institutions
• Agriculture, Fisheries, and Food in the Irish Economy
• Adoption and Economic Impact of Site-Specific Technologies in U.S. Agriculture
• Cash Rents and Land Values in U.S. Agriculture
• Crises and Structural Change in Australian Agriculture
• Biotechnology and Its Application in Agriculture
• Alternative Policies for Agriculture in Europe
• Agriculture and Food Security in Asia by 2030
• Agriculture and Coping Climate Change in Nepal
• Agriculture and Ethiopia’s Economic Transformation
• Culture: Agriculture and Egalitarian Social
• Adaptation, Climate Change, Agriculture, and Water
• Agriculture and the Literati in Colonial Bengal, 1870 to 1940
• Agriculture and Barley Farming Taro
• Agriculture and Agricultural Inputs Markets
• Agriculture and Environmental Challenges
• Challenges for Sustainable Agriculture in India
• Agriculture and German Reunification
• Agriculture and Tourism Relationship in Malaysia Tourism
• 21st Century Rural America: New Horizons for U.S. Agriculture
• Canadian Agriculture and the Canadian Agricultural Industry
• California Agriculture Dimensions and Issues
• Advancements and the Development of Agriculture in Ancient Greece and Rome
• Agriculture and Early Industrial Revolution
• Aztec: Agriculture and Habersham County
• Agriculture and Current Deforestation Practices
• How Has Agriculture Changed From Early Egypt, Greece, and Rome to the Present?
• What Are the Advantages of Using Pesticides on Agriculture?
• Are Digital Technologies for the Future of Agriculture?
• How Did Agriculture Change Our Society?
• Does Agriculture Help Poverty and Inequality Reduction?
• Can Agriculture Prosper Without Increased Social Capital?
• Are Mega-Farms the Future of Global Agriculture?
• How Can African Agriculture Adapt to Climate Change?
• Does Agriculture Really Matter for Economic Growth in Developing Countries?
• Can Conservation Agriculture Save Tropical Forests?
• How Can Sustainable Agriculture Be Better for Americans?
• Are U.S. and European Union Agriculture Policies Becoming More Similar?
• Should Pollution Reductions Count as Productivity Gains for Agriculture?
• Can Market Access Help African Agriculture?
• How Does Genetic Engineering Affect Agriculture?
• Does Individualization Help Productivity of Transition Agriculture?
• Can Spot and Contract Markets Co-Exist in Agriculture?
• How Has Biotechnology Changed Agriculture Throughout the Years?
• Does Trade Policy Impact Food and Agriculture Global Value Chain Participation of Sub-Saharan African Countries?
• Can Sustainable Agriculture Feed Africa?
• How Can Multifunctional Agriculture Support a Transition to a Green Economy in Africa?
• Does Urban Agriculture Enhance Dietary Diversity?
• How Did Government Policy, Technology, and Economic Conditions Affect Agriculture?
• Can the Small Dairy Farm Remain Competitive in US Agriculture?
• What Are the Main Changes in French Agriculture Since 1945 and What Challenges Does It Face Today?
• How Can Marketing Theory Be Applied to Policy Design to Deliver Sustainable Agriculture in England?
• Will African Agriculture Survive Climate Change?
• How Has Agriculture Changed Civilizations?
• Does Urban Agriculture Improve Food Security?
• Can US and Great Plains Agriculture Compete in the World Market?
• The effect of climate change on crop yields and food security.
• Sustainable agricultural practices for soil health.
• Precision agriculture techniques and applications.
• The impact of genetically engineered organisms on crop yields and safety.
• The benefits of agroforestry systems for the environment.
• Current challenges in water management in agriculture.
• The environmental impact of organic farming.
• The potential of urban agriculture to address food insecurity.
• Food waste in the agricultural supply chain.
• Comparing the effectiveness of aquaponic and hydroponic systems.
• Organic vs. conventional farming.
• Can regenerative agriculture combat climate change?
• Agricultural subsidies: pros and cons.
• Should harmful pesticides be banned to protect pollinators?
• Should arable land be used for biofuels or food production?
• Do patent protections of seeds hinder agricultural innovation?
• Agricultural robots: increased efficiency or displaced rural labor?
• Should GMO labeling be mandatory?
• Do the benefits of pesticides outweigh their potential health harms?
• Is it unsustainable to grow water-intensive crops in arid regions?
• The economics of organic farming.
• The need for climate-adaptive crops.
• The role of bees in agriculture and threats to their survival.
• Smart agriculture: transforming farming with data and connectivity.
• The journey of food in modern agricultural supply chains.
• The role of agri-tech startups in agricultural innovation.
• Youth in agriculture: inspiring the next generation of farmers.
• Why should we shift to plant-based meat alternatives?
• The importance of preserving indigenous agricultural practices.
• Smart irrigation systems: optimizing water use in agriculture.

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StudyCorgi . "187 Agriculture Essay Topics & Research Questions + Examples." March 1, 2022. https://studycorgi.com/ideas/agriculture-essay-topics/.

StudyCorgi . 2022. "187 Agriculture Essay Topics & Research Questions + Examples." March 1, 2022. https://studycorgi.com/ideas/agriculture-essay-topics/.

These essay examples and topics on Agriculture were carefully selected by the StudyCorgi editorial team. They meet our highest standards in terms of grammar, punctuation, style, and fact accuracy. Please ensure you properly reference the materials if you’re using them to write your assignment.

This essay topic collection was updated on June 20, 2024 .

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Environmental Resilience and Sustainable Agri-food System Management

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The world is grappling with severe environmental degradation, making environmental resilience a critical priority. Climate change intensifies this challenge, with rising temperatures, shifting weather patterns, and extreme weather events threatening ecosystems and food security. In the agricultural sector, environmental pollution has worsened recently, contributing to soil degradation, water contamination, and biodiversity loss. Restoring the environment and enhancing agricultural resilience is crucial for sustainable agriculture. Addressing these challenges requires integrating environmental resilience with sustainable practices to create agri-food systems that are economically viable and resilient to climate change. This Research Topic aims to develop economically viable strategies that enhance the resilience of agri-food systems to environmental changes while promoting sustainable resource use and ecological balance. By focusing on effective methods to improve environmental resilience, we seek to create agri-food systems that are both profitable and capable of withstanding the challenges posed by climate change. Ultimately, enhancing environmental resilience is crucial for increasing agricultural sustainability and ensuring a stable food supply in the face of a changing climate. High-quality Original Research and Review articles in this field are all welcome for submission to this Research Topic. Research interests include but are not limited to the following areas: • Enhancing environmental resilience in Agri-food Systems • Policy and innovative mechanisms for resilient and sustainable Agriculture • Ecological restoration and biodiversity conservation in Agri-ecosystems • Policy optimization and innovative mechanism towards a resilient Agri-food System • Climate change mitigation and adaptation in agricultural practices • Sustainable agricultural practices management • Resource management in agricultural practices • Climate risk in Agri-Food production and circulation

Keywords : environmental resilience, climate change, agri-food system, sustainable supply chain, resource management

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Agriculture

Browse agriculture topics/papers by subfields, agriculture research papers/topics, farmer's shade tree species preference and evaluation of selected soil physicochemical properties under the tree canopy in coffee based agroforestry systems in deder district, east hararghe z.

ABSTRACT The study was conducted at Deder District, in East Hararghe Zone, Eastern Ethiopia. The aim of the study was to investigate farmers’ shade tree species preference and evaluate selected soil physicochemical properties under and out-side shade tree canopy. To address the objectives of this study, all necessary data were collected through key informant interview, questionnaire survey and soil sampling. A total of 15 key informants and 60 households were participated for preference ran...

ASSESSMENT OF THE PEDAGOGICAL COMPETENCY NEEDS OF AGRICULTURAL SCIENCE TEACHERS IN SENIOR HIGH SCHOOLS IN TAMALE METROPOLIS IN NORTHERN REGION

The purpose of this descriptive study was to assess pedagogical competency needs of agriculture teachers in Senior High Schools in Tamale aimed at determining their perceived level of importance, ability, and most suited training needs based on Borich’s Needs Assessment Model. To keep Senior High School agriculture teachers up-to-date of their pedagogical competency needs, the professional development needs of the agriculture teachers must be assessed regularly for efficiency. Based on the ...

LARGE-SCALE LAND ACQUISITIONS FOR AGRICULTURAL INVESTMENTS IN GHANA - IMPLICATIONS FOR LAND MARKETS AND SMALLHOLDER FARMERS

The participation of large-scale agricultural investors in African land transactions raises concerns about the impacts on a rather hitherto local and smallholder dominated land market. However, there is still limited empirical study on how large-scale agro-investments have influenced changes in land markets and smallholder participation in agricultural land markets in West Africa. Hence, this study examined how large-scale land acquisitions in Ghana have influenced land market changes and imp...

ROLES AND CHALLENGES OF AGRICULTURAL EXTENSION SERVICES FOR FOOD SECURITY IN WA WEST DISTRICT

The Agricultural Sector is important for supplying foods to the world's population. A country's resourcefulness in developing its agricultural sector is an indication of its ability to provide sufficient food for its population. In Ghana, agriculture involves crops, fisheries, livestock and all other related activities. However despite its role, food security still remains a challenge in the Wa West district. The study sought to find out the role and nature of Agricultural extension services ...

PARTICIPATION IN “PLANTING FOR FOOD AND JOBS” PROGRAMME AND COMMERCIALIZATION AMONG MAIZE FARM HOUSEHOLDS IN SAVELUGU MUNICIPALITY, GHANA

Ghana’s “Planting for Food and Job” programme aims to improve farmers’ access to farm inputs. The idea is that through improved access to quality seed varieties, fertilisers and good agronomic practices, output would increase leading to an increased market surplus. This study sought to investigate whether engagement in ‘Planting for Food and Job’ (PFJ) programme influences farm households’ maize commercialization level in Savelugu Municipality, in the Northern Region of Ghana. T...

FACTORS AFFECTING THE ADOPTION OF IMPROVED SORGHUM VARIETIES AMONG FARM HOUSEHOLDS IN NORTHWEST GHANA: A PROBIT ANALYSIS

In an attempt to boost sorghum production, the Savannah Agricultural Research Institute in Ghana, over the years, has released a number of improved sorghum varieties to farmers in northern Ghana. The purpose of this study was to estmate the level of adoption, and to identify the factors that influenced the adoption of the improved sorghum varieties, using a probit model. It was found that age, available family labour, non-farm income, farmers' perception about the varieties, farm size and far...

THE EFFECT OF CLIMATE VARIABILITY ON SMALL-SCALE IRRIGATION FARMERS IN THE SISSALA WEST DISTRICT, NORTHERN GHANA

The government of Ghana and Non-governmental Organizations have constructed a number of small scale irrigation dams and dug-outs in the Sissala West District of the Upper West Region. The purpose of the small scale irrigation dams is to give irrigation farmers access to enough water during the dry season. The variation of rainfall and high temperatures poses serious threat to dams, hence making it difficult for the reservoirs to have enough water for irrigation activities. The study investiga...

GENDER DIMENSIONS OF CLIMATE CHANGE IMPACT ON CROP PRODUCTION AND ADAPTATION STRATEGIES IN THE NADOWLI-KALEO DISTRICT, GHANA

Climate change has become a well-known global issue which has the greatest impact on agriculture which is the mainstay of the people in Nadowli-Kaleo District. Although climate change affects everyone but its impacts are differently distributed among males and females. This study analyzed the gender differentiated impacts of climate change on agricultural production and the adaptation strategies by the farmers in the Nadowli-Kaleo District. The study adopted both qualitative and quantitative ...

FARMERS’ WILLINGNESS TO PAY FOR PRIVATE IRRIGATION SUPPLY IN NANDOM DISTRICT, GHANA

This study investigated farmers willingness to pay (WTP) for private irrigation in Nandom district, Ghana. The study randomly sampled 236 farmers and analyzed data using descriptive statistics and ordered logit regression model. Results revealed that 94.5 percent of the farmers were WTP for private irrigation services with a mean of 35.83 cedis. Farmers’ WTP is determined by income, age, farm size, engagement in an off-farm occupation, labour hours invested in farm operation, yield losses e...

ADOPTION OF GREEN REVOLUTION SERVICES AND POVERTY REDUCTION IN GHANA

In Sub-Saharan Africa (SSA) the technological advances of the Green Revolution (GR) have not been very successful. However, the efforts being made to re-introduce the revolution call for more socio-economic research into the adoption and the effects of the new technologies. The paper discusses an investigation on the effects of GR technology adoption on poverty among households in Ghana. Maximum likelihood estimation of a poverty model within the framework of Heckman's two stage method of cor...

RICE IMPORTATION LIBERALIZATION IN GHANA: IMPLICATIONS FOR SMALLHOLDER RICE PRODUCTION IN NORTHERN GHANA

The case of rice import liberalization in Ghana is an interesting and highly distinctive one. One of the policies of the Ministry of Food and Agriculture (MoFA) is to support an increase in local rice production in order to reduce imports by about 30% as part of efforts to promote food sufficiency. Its strategy aims to increase mechanization, the cultivation of inland valleys, effective and efficient use of existing irrigation systems and further development of irrigation. Ironically, this po...

PROBLEMS TO STANDARDIZATION AND MARKETING OF TRADITIONAL HERBAL MEDICINE IN THE BUlLS A NORTH DISTRICT

Traditional medicine has been in practice in Ghana for several decades and the patronage is high. Several people use it and believe in it. However, traditional medicine in the Builsa North District is not standardized; hence, the research was to investigate the problems to standardization, and marketing of traditional herbal medicine in the Builsa North District in the upper east region of Ghana. Focus was on the discovery of the raw materials for the medicine, the processing and preparation ...

Determinants for rainwater harvesting adoption: a case study of smallholder farmers in Murang’a County, Kenya

Abstract Rainwater harvesting has been practiced among smallholder farmers for centuries in many parts of the world. Recently, it has gained more attention due to the reported increasing water demand and the need for sustainable water management. Drawing on data from a cross sectional survey of 384 household heads (HH), the research study explored the determinants for rainwater harvesting among smallholder farmers in Murang’a County, Kenya. Multistage random sampling technique was employed...

Soil nutrients and crop yield response to conservation-effective management practices in the sub-humid highlands agro-ecologies of Kenya

Abstract Crop productivity in most smallholder farming systems in Sub-Saharan Africa experience low use of soil amendment resources, low and erratic rainfall, frequent dry spells, and droughts. Rain-fed agriculture has a high crop yield potential if rainfall and soil nutrient input resources are utilized effectively. Thus, in 2011, we set up an on-farm experiment in Meru South (sub-humid) and Mbeere South (marginal sub-humid) sub-counties in upper Eastern Kenya to assess conservation-effecti...

The response of soil physicochemical properties to tillage and soil fertility resources in Central Highlands of Kenya

Abstract To attain agricultural sustainability, use of soil resources and tillage requires equal consideration for chemical and physical components of soil fertility. We assessed responses of selected soil physical and chemical properties to tillage and soil fertility amending resources. The study was carried out in Meru South and Kandara sub-counties located in the Central Highlands of Kenya for four cropping seasons. The experimental design was split-plot with tillage as the main factor - ...

Agriculture is the cultivation of land and breeding of animals (livestock), plants and fungi to produce food, feed, fiber and many other desired products to sustain and enhance life. The study of agriculture can lead to a variety of careers, including those associated with consulting, farming, management and research. Afribary publishes latest agriculture topics for students. Browse through Agriculture projects, agriculture project topics, Agriculture thesis, seminars, research papers etc. All papers and research works in agriculture and its sub-fields.

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The agricultural community needs to improve nutrient use efficiency for modern cropping systems to ensure agronomic viability and environmental quality. This will require a different approach to nutrient management: the use of adaptive management concepts and processes. This project will develop technical and educational tools to encourage adaptive management.

The expansive growth of solar photovoltaics (PV) in Massachusetts has helped make the state a leader in renewable energy production, but there have been public concerns regarding the development of agricultural lands for solar PV electricity production. In response to these concerns, the Massachusetts Department of Energy Resources (DOER) included provisions in the new state solar energy program which limit conventional ground-mounted solar arrays on farmland, while encouraging innovative "dual-use" technology. Under the new Solar Massachusetts Renewable Target (SMART) program, there is a significant financial incentive for dual-use systems which limit shading and obstructions, and require continued agricultural production on the land below and around solar arrays.

People depend on vegetables to provide major portions of the nutrition for healthy diets. For several years, the mineral nutrient elemental concentrations in vegetables has declined. The decline has been associated with the development of new cultivars of vegetables that have lower concentrations of nutrients than heirloom cultivars. Breeding of crops for accumulation of nutrients has potential for developing nutrient-rich vegetables but has not received much attention in genetic improvement of vegetables.  Cultural practices may give great and practical process for enhancing nutrient concentrations in vegetables, and cultural practices concerning fertilization to enhance nutrients in vegetables will be a priority in this project. Organic fertilization of crops is required for certification of organic produce. Producing equal yields and equal nutrient contents in organically fertilized vegetables compared to vegetables fertilized with chemicals are challenges. The research in this project will evaluate cultural methods that may be employed to enrich nutrient contents in vegetables through practices of fertilization organically or conventionally.This project includes a series of related experiments to assess nutrient accumulation in vegetables, primarily lettuce, in response to selection of cultivars of crops and management of fertilization. Organic fertilization will be compared to conventional practices of fertilization to determine growth and composition of lettuce in field plot and greenhouse investigations. Investigations concerning hydroponic production and modification of soil-based or peat-based media with organic or microbial amendents will be conducted to assess the effects of these amendments on productivity and nutrient composition of produce from vegetables.

Nanoparticles (NPs) are defined as particles with at least one dimension smaller than 100 nm. As particle size decreases the reactivity of the surface atoms could increase dramatically. These unique properties make nano-sized particles valuable engineering materials because of their extraordinary strength, chemical reactivity, electrical conductivity, or other characteristics that the same material does not possess at the micro- or macro-scales. ENPs are being exposed to different environmental niches via deposition of airborne NPs, application of agrochemicals containing NPs, accidental spills, land application of sewage sludge biosolids, and landfill leachates. There the environmental risks of ENPs are attracting increasing attention from both the public and scientific communities due to their toxicity to organisms. The main pathways through which MNPs are introduced to arable soils are the application of sewage sludge (biosolids) and irrigation with treated wastewater. These agricultural practices are common in many countries including USA. Contamination of agricultural soils with ENPs is of great concern due to their uptake by crops, thus posing the problem to food safety and exposure to humans. To ensure safe application of biosolids and irrigation with treated wastewater containing ENPs, there is an urgent need to investigate the fate of ENPs in the soil-water-planMass Agricultural Experiment Stationt system and to evaluate the associated risks. Therefore, this research will determine the environmental fate and process of several types of ENPs and their plant uptake and translocation in soil-water-plant systems. Also, we will study how ENPs affect the availability and uptake of other contaminants (e.g., metals and antibiotics) by plants. The results of this study are expected to help us understand how these ENPs interact with soil and water reactive components (e.g., DOM, clays). In addition, we will better understand the retention, bioavailability, uptake and translocation, transformation and phytotoxicity of ENPs in soil-waterplant system. Also, we can provide useful data for assessing the mobility, exposure and risk of ENPs in agriculture and the environment in general.

This research continues exploration of biological (non pesticide) control of a series of invasive plant and insect species that affect crops and forests.

African trypanosomes are flagellated protozoa that cause sleeping sickness in people and Nagana in domestic animals. These diseases are fatal if left untreated. The diseases are endemic in the humid and semi-humid zones of Africa affecting a landmass of 10 million km 2 and 36 countries. Trypanosomiasis precludes cattle-based agriculture from much of this area and threatens up to 60 million people, of whom about a half million are presently infected.

It is known that legumes generally respond to existing N in the soil. When soil N is relatively high, legumes prefer to use soil N rather than to engage in symbiosis with rhizobia. However, the ecophysiological responses of legumes to existing soil-N level and the changing climate - including temperature changes and precipitation dynamics impact rhizobia nodulation - have not been studied in actual field conditions. This study seeks to understand these responses in order to improve N management, maximize the benefits of legumes, reduce off-farm inputs, and enhance soil health. Moreover, growth and N accumulation of legumes is heavily dependent upon the nitrogen-fixing performance of the microbial partner recruited by the host legume. Native rhizobia strains in the Northeast that associate with faba bean (Vicia faba) and sunn hemp (Crotalaria juncea), two multi- purpose legumes newly introduced by the current project team to the area, have not been identified. In this project, native strains will be recovered from nodules, genetically sequenced, and their performance will be compared with elite strains maintained at USDA.  

This research will examine possible affects of climate change on certain agricultural crop plants. It will include experiments that will allow prediction of how timothy and alfalfa plants will respond to future elevated CO2 and O3 levels.

This research involves modeling of cell growth, metabolite production rates, and product yields on various feedstocks using a variety of target organisms that can perform the bioprocess. These emphases need to be addressed prior to commercial implementation of generation of biofuels and industrial precursors from hydrothermal vent microbes.

The market for specialty foods targeted for Latino populations is especially strong in New England. While most of these foods are imported, many can be locally grown, offering a strong and increasing market for local farmers. We will work to evaluate germplasm of Latin American specialty crops with the objective of identifying parental materials to initiate a breeding program for these crops.

This project focuses on male equine infertility from several perspectives: 1) understanding at the molecular level the mechanisms of the causes of male infertility; 2) Methods to be developed during this project could easily be translated to standardized tests in the clinical laboratory; 3) Understanding of male infertility at the molecular level could provide rational strategies to treat infertile stallions and/or improve assisted reproductive technology.

This project will develop and diversify Crambe (an oilseed crop) and brassica (mustard green) species as dedicated bioenergy crops for biodiesel production. The proposed strategy will increase crop biomass and seed yields while growing these crops on marginal and heavy-metal-contaminated lands, thus increasing both yield and arable acreage.

This effort will develop local production and post-harvest practices to assist Massachusetts farmers to produce high quality Chinese medicinal plants with uniform levels of bioactive constituents. This will ensure the type of plant material desired by practitioners of acupuncture and Oriental medicine. This will benefit growers, practitioners, and those in need of healthcare. The establishment of Chinese medicinal herbs in Massachusetts could provide an income source for small farms and help maintain rural farmland.

This project will explore the hypothesis that development of an effective LAMP assay (loop-mediated isothermal amplification) for livestock and avian chlamydiosis will lead to significant reductions in zoonotic disease as well as morbidity, mortality and the reproductive health of farm animals.

The goals of this project are to supply apple growers with new tools that will enable them to continue towards a goal of sustainability while providing local consumers with a safe and healthful supply of fruit. As such, it will research new methods, educate growers, and engage consumers and wholesalers in Integrated Pest Management.

In this project, we will focus on key pest and water management practices for large-fruited, high-yielding cranberry hybrid cultivars. Cranberry fruitworm (CFW) is the most damaging pest insect in MA cranberry and presents a significant hurdle to maximizing yield. An understanding of pest-host dynamics is the key to managing this pest but has yet to be developed for new high-yielding cultivars, especially those most recently introduced. Weed management is critical to long-term sustainability and profitability for cranberry growers since weeds primarily compete with cranberry vines for water, nutrients, and space (Patten and Wang 1994). Herbicides are an important and critical tool needed to ensure proper colonization and vine health during establishment and for the life of the bed. However, we have very little information on the susceptibility of new hybrid cultivars to currently registered herbicides. Fruit rot, a complex disease caused by at least 15 different fungal species, is responsible for a majority of grower losses ascribed to 'poor quality' and is often especially a problem on young beds. In recent years, chlorothalonil fungicide has been the backbone of management for this disease but changes in the European Union have eliminated its use on fruit destined for that market. Most of the alternative materials have specific modes of action that present a higher risk of developing fungicide resistant pathogen populations. A potential contributing factor to poor fruit quality (rot and lack of firmness) is irrigation management both in regards to soil moisture and in its use for cooling the plants. The 2012 Farm Bill identified specialty crop production and research as priorities. This entire project addresses challenges to the production of a specialty fruit crop. USDA priorities for specialty crops research include threats from pests and diseases. Climate change and water are priorities for NIFA programs. In addition, the research proposed is aligned with grower-identified priorities (Cape Cod Cranberry Growers Association, Cranberry Institute). The primary beneficiaries of this research will be Massachusetts cranberry growers and the handlers who receive the fruit. Growers and handlers in other cranberry regions of the U. S. (Wisconsin, New Jersey, Pacific Northwest) will benefit to the extent that much of the knowledge gained in this project will be transferable to those regions.

Threats to the sustainability of cranberry production in MA and elsewhere in the U.S. come from many sources: consumer demands for sustainable but inexpensive products, commodity pricing in an industry that is currently over-supplied with juice concentrate, changes to industry fruit quality standards, rising costs for energy and pest management products, and changing standards in pesticide use to accommodate global marketing.

 Despite the fact that plants are a rich source of novel molecules, valuable to both basic and applied sciences, only a fraction of the pathways and compounds in plants have been explored. The project proposed here seeks to discover novel plant-produced natural products with unique and valuable properties, as well as the genes and pathways involved in their synthesis. At the core of this effort is an extensive living Plant Cell Culture Library (PCCL) that was recently (2014) donated to UMass by Monsanto.

This project proposes to capture DNA sequences from armored scale insects intercepted at plant quarantine stations, while carefully identifying each specimen in the traditional way by mounting on a microscope slide. The results -- DNA sequences from well-identified specimens—will help us develop a DNA-based system of identification, and also contribute to improving our understanding of the history and diversity of armored scale insects and their relationships with their host plants.

Due to the freeze on the night of May 18th, many fruits were severely injured and subsequent thinners were either not applied or, if they were, used at low rates. It was observed that many fruits had a reduced number of seeds, however fruit harvested were very large. This project is to see if a relationship between seed number and fruit size exists. At normal harvest, large fruits were selected and fruit was weighed. Fruit diameter and the number of aborted and viable seeds were recorded for each apple. There was no correlation between fruit size and seed num

This project will examine methods to control undesirable sprouting in potatoes through breeding, transgenic strategies, or environmentally friendly agents.

This study is expected to reveal differences in one or more aspects of immune components and will aid in the understanding of how chronic exposure to certain organic pesticides may alter immune responses.

This projects involves two aspects of equine operations: manure handling and a comparison of footing materials. This project will evaluate two simple low cost aerated static composting systems for typical small acreage horse and/or livestock operations. In addition, it  will evaluate various footing materials and provide the cost of operation and materials for each used material.

The diverticulated crop organ of the common house fly, which is the major insect vector of numerous human food pathogens (e.g., Escherichia coli) is the major reservoir or storage area for this, and other, important food pathogens. It has also been demonstrated that this is where horizontal transmission of antibiotic resistance to E. coli occurs. Thus, the diverticulated crop organ is an essential component in the transmission cycle between pathogens and human foods/food crops. At the same time, the salivary glands of house fly are directly involved in vectoring pathogens and, are intimately involved in pathogen transmission. Almost nothing is known about the physiological factors involved in the regulation of both crop filling and emptying of the adult house fly. Even more concerning is that we know even less about the effect of various pathogens, either food pathogens or pathogens of the house fly vector, on salivary gland regulation. What effect does the salivary gland hypertrophy virus have on normal crop organ function? A better understanding of how these two essential organ systems are regulated, will give researchers a better picture of how to use this information to explore novel, non-chemical control strategies that can be directed at interfering with the normal regulation of these two organ systems. Ultimately, non-traditional control strategies will be developed that rely on interfering with the function of these two organ systems, both of which are essential to the fly. It is the objective of this project to develop non-traditional control strategies, thus reducing fly resistance to insecticides. Thus, by compromised longevity of the vector, pathogen vectoring, and/or reproductive development of the flies can be interfered with resulting in death, abnormal flight ability, and or reduced fecundity.

Current knowledge of the molecular mechanisms governing plant iron uptake and translocation is limited, as is our knowledge of how these processes are controlled at the molecular level. During this project, we will use molecular, biochemical, and physiological approaches to better understand mechanisms of nutrient (i.e., iron) uptake, a stated goal of the National Institute for Food and Agriculture (NIFA). The focus of this proposal is on gene discovery, an engine for crop improvement in two important ways. Most obviously, understanding of the molecular mechanisms responsible for iron uptake and homeostasis is a requirement for genetic engineering approaches to crop improvement. Without knowledge of the genes involved, we cannot know what engineered approaches could be taken. However, public acceptance of engineering approaches is limited, and partly because of this, breeding approaches have been extremely important in currently used efforts to enhance the iron concentration in the edible parts of plants. Many studies have identified quantitative trait loci (QTL) that have small effects. Discovery of additional genes will be essential in identifying the genes underlying these QTL and in understanding their function. At present, limited mechanistic knowledge limits our ability to understand these genes.

Optimal food production by plants requires a sufficient supply of soil nutrients, the most limiting of which is nitrogen. Sustained agricultural productivity has historically been maintained in the rich world by copious application of synthetic nitrogen fertilizers, with high cost to the economy and the environment. Unique among crop species, legumes produce their own nitrogen nutrient through a symbiosis with nitrogen-fixing bacteria collectively known as rhizobia. In this symbiosis, the bacteria convert molecular nitrogen into ammonia in exchange for host photosynthate. Studying the nitrogen-fixing symbiosis and fully explore its potential can boost the productivity of legume crops in the short term, and may expand this ability to non-legume crops over the long run. However, the nitrogen-fixing symbiosis is a complex system, and currently we know too few of the molecular players involved. This project will optimize two methods to reduce the activity of a given gene, and use these methods to screen for legume genes required for the function of the nitrogen-fixing symbiosis. The result of such endeavors should be a comprehensive list of legume genes playing critical roles in interacting with their rhizobial symbionts, and help unveal crucial biological processes in the interaction between plants and beneficial microbes.

This project addresses, via research and Extension, two important pests affecting tree-fruit and berry production in Massachusetts, the Plum Curculio and the Spotted Wing Drosophila.  The main goal of this project is to evaluate the attractiveness of aromatic compounds to overwintered plum curculio and to other early season pests.

Current agricultural practices on available arable land will not meet the nutritional needs of a population that will reach nine billion people by the middle of this century (Ray et al. 2013). In parallel, climate change will increase extreme weather events, including drought (Dai, 2011, Trenberth et al., 2014), and continued urbanization of farmland is eliminating arable land (Song et al. 2015). There is a clear need for sustainable agricultural innovations that can increase yields and provide food security without incurring environmental degradation. Soil microbes are known to form associations with plants and affect plant health, and in recent years, interest has grown in exploiting the beneficial associations that plants establish with microbes. The plant microbiome abounds with plant growth-promoting rhizobacteria (PGPR) that can help plants acquire more nutrients from the soil and tolerate stressors like drought (Barnawal et al. 2013, Bresson et al. 2014). PGPR can also control plant pathogens (Chowdhury et al. 2013), promote beneficial mycorrhizal colonization (Labbe et al. 2014), and produce potentially valuable secondary metabolites (Raaijmakers et al. 2012). Finding ways to harness these beneficial microbes to improve crop growth and yield has the potential to ameliorate the challenges imposed by the world's growing population and environmental degradation.

Deficiencies of mineral content in human diets, a causal factor in rising rates of malnutrition worldwide, appear to derive from diminished contents of mineral nutrients in foods of plant or animal origins.This project will provide a foundation of data to help ascertain if the nutrient content of foods can be enhanced through selection of crop varieties and improved nutrition of crops and will assess how dietary habits affect mineral nutrition of humans.

Rootstocks are the most critical element in any orchard system.  It controls disease and insect susceptibility, tree vigor, treeproductivity and fruit quality and maturation.  Many new rootstocks become available annually, and our work evaluates those rootstocks under Massachusetts conditions.  Compiled with evaluations from across North america, we are able then to make very good recommendations regarding rootstock use in orchard systems.  Expected outcomes include increased orchard profitability and a general reduction in orchard canopy volume.  the latter results in lower pesticide requirements.  Further expected impacts include improved fruit quality. 

Three temperate forage grass species (Lolium perrene, Festuca arundinacea, and Dactylis glomerata) will be grown in 6x10 ft plots under field conditions over the summer at the University of Massachusetts Crop and Animal Research and Education Farm in South Deerfield, Massachusetts. Each species will be grown in 10 replicates for a total of 30 plots. Five replicates of eachs pecies will be treated as well-watered controls and their soil moisture maintained above 25%, while the other five replicates will remain under a water-reduced treatment, receiving no rain or supplemental water. Water reduction will be imposed through the use of rain-out shelters. The shelters will have sides that could roll up and down in order to maintain ambient temperature and allow maximum air flow through the plots on dry days, but will be rolled down on rainy days to keep the water out. Water-reduction conditions will last for 10 weeks, after which rain shelters will be removed and rewatering begins over a period of three weeks in order to stepwise return soil moisture content to above 25%.

Microbial community composition: Throughout the water reduction period, bacterial communities will be sampled once a week for a total of 10 samples and an additional three times during the recovery period. Several mature but not senescent leaves will be collected from each plot for DNA extraction and bacterial cell counts in order to capture a representative community of the whole plot. Samples will be prepared for 16S rRNA sequencing using the Illumina MiSeq platform in two separate pools.  Plant health measurements: To understand how bacterial communities change in relation to changes in the plant, several plant health measurements will be taken. Leaf relative water content, electrolyte leakage, chlorophyll, and soil moisture will be measured every week. Additionally, non-destructive biomass measurements will be taken periodically by measuring leaf height and plot coverage. Plot coverage will be estimated using an elevated quadrat device. At the end of the water reduction period, plots will be divided in half and destructive biomass sampling of one half will provide above ground fresh weight and dry weight measurements. Additionally, roots will be sampled in 15 cm increments to a depth of 60 cm. After soil removal roots will be dried and dry mass measured. 

Nitrogen fixation rates by leaf microbes: Samples will be collected during field studies in the summer and used to quantify potential and actualized nitrogen fixation in the phyllosphere. Additional questions will be focused on understanding how phyllosphere BNF is impacted by plant host species, temporal dynamics, drought, and recovery. To determine the rate of BNF,stable isotope probing will be conducted at 6 different time points. Three samples will be taken during the drought period (week6, 7, 10) and three each week during recovery. Rate of nitrogen fixation will be determined by measuring incorporation of thestable isotope 15N into the leaf tissue. Leaf cuts of known area will be incubated in an artificial atmosphere containing 80% 15N and 20% O2 for 48 hours under ambient light and temperature. Corresponding control samples will be incubated under normal atmosphere to determine natural 15N abundance. After incubation, samples will be dried at 70°C, weighed, finely ground, and 1-2 mg of plant powder will be weighed in tin capsules and sent to a collaborator at the University of Vienna to determine 15N incorporation using a continuous-flow isotope ratio mass spectrometer.  Nitrogen fixation rates can then be determined using the following equation where Nleaf is foliar N concentration, Mr is molecular weight of 15N, and t is incubation time:N2-Fix = Nleaf x (at%15Nsample - at%15Ncontrol)/100 x 103/Mr/tBacterial DNA samples corresponding to each timepoint will be taken to determine the absolute abundance of nitrogen fixing bacteria at each time point as well as to determine their taxonomic identity. The absolute quantity of nitrogen fixing bacteria per leaf area for each of the grass species and treatments will also be determined for the same time points using qPCR of the nifH gene. Next, the rate of nitrogen fixation per nifH copy number will be determined for each grass species under normal and water-stressed conditions. By comparing the three grass host species we will gain a better understanding of how phyllosphere BNF inputs are impacted by plant host species. By directly comparing rates under normal and stressed conditions we will understand how BNF will be influenced in the future by climate stress. Identification of nitrogen fixing members of the bacterial community will be achieved by sequencing the phylogenetic marker genes nifH using the Illumia MiSeq platform. nifH identity,diversity, and richness will be added to the models to better understand biological nitrogen fixation in the phyllosphere.

The herbal and botanical product market, estimated at more than US $60 billion in 2003, has been increasing at 6 to 8 % per year. According to the United Nations Comtrade Statistics, the estimated size of the global market for essential oils, fragrances, and flavors in 2013, was US $26 billion, growing an average rate of 8.1% in the past five years. The market for herbal dietary supplements in the United States has reached an estimated total of $6.4 billion, increasing by 6.85% in 2014 as compared with the previous year. Improvements in production of medicinal and aromatic plant products are needed to meet increased market demands.

Early studies have demonstrated that soil microorganisms associated with plant roots can improve plant growth and development through various mechanisms, including increasing available nutrients to plants, synthesizing phytohormones, inducing plant stress tolerance, and suppressing pathogens. Although the mechanisms are not fully understood, studies have demonstrated that the use of soil microorganisms (PGPRs) can promote synthesis of secondary metabolites in plants, improving the quality and value of the medicinal and aromatic plants. While commercial PGPRs and mycorrhizal fungi are available for various grain crops and vegetables in the United States, few of these products are available for medicinal and aromatic plants.

In the proposed study, PGPRs and mycorrhizal fungi will be studied for the growth and secondary metabolite synthesis in the Lamiaceae and other herbal families for their use in culinary and essential oil products. The development of PGPRs and mycorrhizal treatment that improve medicinal and aromatic plant yields and secondary metabolite production can lead to increased profits for growers and industries using natural products.

Literature on food composition demonstrates that the mineral nutrient density of vegetables has fallen in the past 50 years. This decline is associated with two factors: declines in soil fertility and with the genetics of plant cultivars that accumulate yield at higher rates than they accumulate mineral nutrients. This research is intended to help develop systems of food crop production that will supply adequate mineral nutrition to people directly through crop-derived foods.

Utilizing food systems to improve nutrition without the need for artificial fortification of food or use of dietary supplements of mineral nutrients is important in ending malnutrition. Malnutrition from deficiencies of mineral elements is reported to be on the rise worldwide, even in the United States. It is estimated that half of the world population suffers from incidences of mineral nutrient deficiencies. These deficiencies limit the physical, intellectual, and mental health activities of the affected people. The deficiencies appear to derive from diminished contents of mineral nutrients in foods of plant (vegetables, fruits) or animal (meats, milk, cheese) origins. With fruits and vegetables, the decline in nutrients is related in part to depletion of nutrients from soils without adequate replenishment with fertilization. Some of the diminished nutrient contents in fruits and vegetables may be related to genetics of new cultivated varieties of produce. Research is needed to develop systems of food crop production that will supply adequate mineral nutrition directly through crop-related foods and from meats and dairy products from livestock and poultry that are provided with adequate mineral nutrition. The research proposed under this project will provide a foundation of data obtained through field, greenhouse, and laboratory research to enable the investigators to pursue studies in planning sustainable food systems for human nutrition and crop production. The research will allow the investigators to obtain data that will help to ascertain if the nutrient content of vegetables and fruits can be enhanced through selection of crop varieties and improved nutrition of crops through fertilization and soil amendments.

This project has three components to increase sustainability in Massachusetts cranberry production:

• development and demonstration of sustainable practices for the management of the most severe pest problems: cranberry fruitworm, fruit rot disease, and the parasitic weed dodder.
• investigation of practices to conserve water and fuel.
• work with growers to implement nutrient management Best Management Practices (BMPs).

This research project seeks to develop better understanding of the iron homeostasis process in corn in order to address biofortification of staple foods with iron.

During estrus, mares can behave in a manner that can make handling, riding, training, or competing these horses difficult. Current methods to suppress estrus behavior during the breeding season, when most horse competition takes place, include: pharmacological treatments; glass marbles; and negative reinforcement. This work will develop strategies to control estrus behaviour without the need for pharmacological treatments or negative reinforcement.

Laminitis is a crippling disease that affects about one-percent of the more than nine million horses in North America, at a cost of over $1 billion annually. The goals of this project are to identify the specific metalloproteinases responsible, in hope of identification of inhibitors that can protect horses at risk.

Plant diseases cause crop loss, reduce food production and threaten global food security (Savary et al., 2012). Focusing on two distinct pathosystems that cause Fusarium vascular wilts and the Basil downy mildew (BDM), respectively, we propose to establish a pipeline to dissect host-pathogen interactions and provide novel means to develop disease resistant cultivars in order to manage plant diseases that threaten food security.

This project, a component of a larger effort to annotate the bovine genome (define genes within the genetic code). One goal is to determine whether variations are associated with enhanced or decreased resistance to infectious diseases. We are interested in their receptors that detect the presence of infectious agents as well as the molecules these cells may produce to communicate with other cells in the immune system (known as cytokines or interleukins).

The relationship between domesticated animals and humans is a close one, and has existed for at least ten thousand years. It is important to understand the immune defenses of many animals, in addition to the immune defenses of humans and mice. The goal of our project is is characterize the genetic diversity of a family of immune receptors in domesticated animals and use this information for selective breeding and the design of better vaccines.

Evaluate pasture management systems with beef and other livestock.

Preventative and therapeutic reproductive management strategies...that are not drug-base will improve animal reproductive performance.  This is a key part of sustaining an agricultural production system that is highly competitive in the global economy. The research proposed here will focus on several important areas. The team continues to conduct studies to identify novel genes and cell function that might contribute to predicting oocyte quality.  The expression of factors that regulate luteal development, function, and regression are also central to improving female fertility in dairy and beef cattle. Likewise, environmental and metabolic stress negatively impact embryonic and fetal survival in cattle and sheep; and therefore, represent an additional area of research focus.

This project is intended to develop effective ways to keep fruit on trees until mature. It is also evaluating the effects of the methods on fruit quality and storage potential.

This project takes a theoretical and empirical approach to study how several aspects of the food supply chain affect the decisions of consumer and firms and their well-being. The research is examining three issues: buyer market power, the vertical structure of markets and benefits and costs associated with mandated labeling of food products.

This multidisciplinary project will promote the use of biochar and bio-oil generated from agricultural/forest organic wastes to enhance small farm sustainability through providing renewable fuel, and improving soil quality and crop productivity, and to improve the environment through sequestrating greenhouse gases and reducing the mobility and exposure of contaminants in soils.

In maize and the grass family, programmed cell death has a particular role to play in floral development. Maize flowers are initially hermaphroditic, but become either male or female through differential organ abortion. In male flowers, the female floral organs (the carpels) stop growing after they have formed, and eventually undergo programmed cell death. Programmed cell death in the carpels of the male maize floret is partially under the control of the transcription factor grassy tillers1. In gt1 mutants, the carpels in male flowers do not abort completely (Whipple et al.; Bartlett et al., 2015). However, gt1 mutant flowers are not fully hermaphroditic, indicating the existence of other genes that act with gt1 to regulate carpel abortion and programmed cell death. Which other genes are involved in carpel abortion? How do they interact with known sex determination genes in maize?

We have designed a series of genetic experiments geared at answering these questions. We will use mutant analysis to investigate whether gt1 is part of known sex determination pathways in maize. In addition, we have isolated four maize mutants where the gt1 mutant phenotype is strongly enhanced and programmed cell death in male flowers is disrupted. Using genetic and genomic tools, we will identify the genes that have been disrupted in these mutants, and work to determine their precise roles in mediating growth repression and programmed cell death.

We will develop a mathematical model that predicts how farmers (or firms) will make decisions when choosing between two markets. The markets we will study include a wholesale market, where farmer's products are no different from all other farmers, and a farm-to-school market where the farmer's products are differentiated (the farmer is known and the products are known to be locally produced). We will then design economic experiments that could be used to test the model's theoretical results. Plans for the design will focus on determining how farmers will allocate their products among the two markets given different levels of transaction costs and market power. We will also work on the design of a preliminary experiment to determine the social preferences of the "farmers." The choices of these "farmers" will then differ according to their social preferences, the transaction costs they face in marketing their products, and the amount of market power they possess and the school possesses.

This research will examine possible affects of climate change on certain agricultural crop plants. It will include experiments that will allow prediction of how alfalfa plants will respond to future elevated CO2 (800ppm) and elevated ozone (O3) (80ppb).

This project will examine the effect of natural diversity on biofuel production efficiency by using a grass energy model organism (Brachypodium distachyon) , and treatment with both biological and thermochemical conversion.

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Efficient topic identification for urgent MOOC Forum posts using BERTopic and traditional topic modeling techniques

• Open access
• Published: 17 September 2024

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• Nabila Khodeir   ORCID: orcid.org/0000-0002-6178-5820 1 &
• Fatma Elghannam 1  

MOOC platforms provide a means of communication through forums, allowing learners to express their difficulties and challenges while studying various courses. Within these forums, some posts require urgent attention from instructors. Failing to respond promptly to these posts can contribute to higher dropout rates and lower course completion rates. While existing research primarily focuses on identifying urgent posts through various classification techniques, it has not adequately addressed the underlying reasons behind them. This research aims to delve into these reasons and assess the extent to which they vary. By understanding the root causes of urgency, instructors can effectively address these issues and provide appropriate support and solutions. BERTopic utilizes the advanced language capabilities of transformer models and represents an advanced approach in topic modeling. In this study, a comparison was conducted to evaluate the performance of BERTopic in topic modeling on MOOCs discussion forums, alongside traditional topic models such as LDA, LSI, and NMF. The experimental results revealed that the NMF and BERTopic models outperformed the other models. Specifically, the NMF model demonstrated superior performance when a lower number of topics was required, whereas the BERTopic model excelled in generating topics with higher coherence when a larger number of topics was needed.The results considering all urgent posts from the dataset were as follows: Optimal number of topics is 6 for NMF and 50 for BERTopic; coherence scores is 0.66 for NMF and 0.616 for BERTopic; and IRBO scores is 1 for both models. This highlights the BERTopic model capability to distinguish and extract diverse topics comprehensively and coherently, aiding in the identification of various reasons behind MOOC Forum posts.

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• Artificial Intelligence
• Digital Education and Educational Technology

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1 Introduction

Online education has the ability to cater to a wide range of learning preferences and styles. Multimedia-rich course materials, interactive simulations, and personalized feedback mechanisms can enhance the learning experience and foster deeper engagement (Dhawan 2020 ). This diversity has enabled educational institutions to better meet the diverse needs of their students, even in the face of many challenges (Hodges et al. 2020 ). In addition, accessibility has been a major factor in the growing importance of online education. By transcending geographical barriers, online platforms have democratized education, enabling learners from diverse backgrounds to access high-quality educational resources regardless of their physical location (Zawacki-Richter 2021 ). This has proven to be particularly beneficial for individuals with disabilities, caregiving responsibilities, or those living in remote or underserved areas, who may have faced significant barriers in traditional educational settings (Hodges et al. 2020 ). The COVID-19 crisis has also accelerated this trend as it has thrust online learning into the spotlight as a vital component of modern academia (Bates 2015 ). This forced educational institutions to quickly adapt and adopt distance teaching methods (Dhawan 2020 ). This rapid transformation has underscored the inherent advantages of online education, which include increased accessibility, flexibility, and the ability to accommodate diverse learning styles (Bozkurt and Sharma 2020 ).

Massive Open Online Courses (MOOCs) have emerged as a significant educational advancement, gaining widespread adoption across various institutions worldwide. In these courses, students engage with pre-designed materials and undertake independent study as a major component of their learning process. However, interaction plays a pivotal role in online learning, including MOOCs, ensuring the quality of education (Trentin 2000 ).

To enhance students’ learning experiences and performance, monitoring their interactions and addressing their requirements effectively is crucial. MOOCs provide forums facilitating communication between learners and instructors, enabling them to engage in discussions and seek support (Alyssa Friend Wise and Cui 2018 ) However, the effectiveness of traditional student-to-instructor communication faces challenges in the MOOC context due to the sheer volume of students involved and the diverse range of learner backgrounds, needs, and objectives (Jacobsen 2019 ).

Notably, while learners generate a substantial number of posts throughout the course, only around one-fifth of these posts are considered urgent and require immediate attention from the instructor (Akshay Agrawal et al. 2015 ).

To deliver a high-quality learning experience, it is essential to prioritize the identification and analysis of learners’ urgent requests (posts) and promptly address them by notifying the relevant department. Previous studies have categorized learners’ requirements into urgent and non-urgent categories (Almatrafi, Johri, and Rangwala 2018 ; Khodeir 2021 ; El-Rashidy et al. 2024 ). This analysis can aid instructors in managing many posts and prioritizing their answers.

However, tackling the issue only as a classification issue without considering the context of the learners’ requests limits the ability to accurately identify the specifics of the request, which in turn assists in taking the necessary action in this respect. Urgent posts within the discussion forums can cover various topics and issues. Learners may seek immediate assistance for problems, clarification on course materials, guidance on assignments or exams, or even express concerns about technical difficulties. Urgent posts can also be related to administrative matters such as registration issues, grading problems, or questions about course policies.

There is a growing demand for automated techniques to analyse and understand these urgent posts’ content to address this challenge. Natural Language Processing (NLP) and machine learning techniques can automatically identify and categorize urgent posts based on their topics and content (Alrajhi and Cristea 2023 ; Zankadi et al. 2023 ). By leveraging these techniques, administrators can efficiently prioritize and respond to urgent posts, ensuring learners’ needs are met and issues are resolved promptly.

Topic modelling uses unsupervised machine learning techniques. Without labeled data, topics are identified by counting words and grouping similar word patterns. Topic models can group similar documents and build new connections between topics, which can assist in organizing and provide insights for understanding a large corpus (Abdelrazek et al. 2023 ). Compared to supervised algorithms, it requires less manual effort because it does not need to be trained on data manually labelled by humans.

Topic modelling is defined as finding topics, as weighted sets of words that best represent the information of the documents (Angelov 2020 ). Several models are used to create such topics. Generative probabilistic models, such as Latent Dirichlet allocation (LDA) (David M Blei, Ng, and Jordan 2003 ; D. Blei 2001 ), Latent Semantic Indexing (LSI) (Landauer, Foltz, and Laham 1998 ; Landauer et al. 2013 ), and Non-Negative Matrix Factorization (NMF) (D. Lee and Seung 2000 ; Xu, X. Liu, and Gong 2003 ) are well-known traditional approaches to perform topic modeling.

Latent Dirichlet Allocation LDA is the most famous method for topic modeling. LDA is an unsupervised clustering technique proposed by Blei et al. (David M Blei, Ng, and Jordan 2003 ) used for text analysis. It is a generative probabilistic model in which each document is considered a distribution of topics, and each topic is considered a distribution of words (Guo and J. Li 2021 ). The LDA model has two hyperparameters: Alpha ( α ) and Beta ( β ). The distribution of document topics is controlled by ( α ), while the distribution of topic words is controlled by ( β ). All MLbased /or LDA approaches fundamentally treat the corpus as a bag of words to get the initial document term matrix, which means it does not consider word order, synonyms, syntactic information, the semantics of words, etc. Despite their usefulness in text analysis, LDA models have a notable disadvantage: they can produce ambiguous or inconsistent topics, particularly when dealing with noisy, sparse, or diverse data (Jelodar et al. 2019 ).

Latent Semantic Indexing (LSI) is a traditional topic modeling technique used to explore relationships between a large set of documents and the terms they contain. It identifies word usage patterns across the documents and grouping terms with similar patterns (Dumais 1994 ; Kontostathis and Pottenger 2006 ).

Non-Negative Matrix Factorization (NMF) (D. D. Lee and Seung 1999 ) is popular unsupervised topic modeling technique for reducing the dimension of the input corpora. It uses the factor analysis method to give the words with less coherence comparatively less weight (D. Lee and Seung 2000 ), and it has been widely used to discover the underlying relationships between texts and identify latent topics (Arora et al. 2012 ).

BERT, Bidirectional Encoder Representations from Transformers (BERT) from Google (Devlin et al. 2018 ), has become the focus in recent years for achieving state-of-the-art performance in several NLP tasks (Grootendorst 2022 ). The BERT embeddings model provides an improvement for the context dependency issue. This model is context-sensitive, with each word containing a variety of embeddings de- pending on where it appears in the sentence. It achieves good results in generating contextual word and sentence vector representations. The impressive results of Bert’s pretrained language representations inspired the creation of BERTopic. BERTopic is an end-to-end topic modeling tool that utilizes BERT embeddings and a class-based term frequency-inverse document frequency (c-TF-IDF) to create dense clusters. In contrast to the traditional document-level TF-IDF technique, the class-based TF-IDF procedure models the importance of words in clusters rather than individual documents. This makes it possible to produce topic-word distributions for every cluster of documents (Grootendorst 2022 ). BERTopic technique creates topic representations based on four key components: First, embedding, which involves con- verting documents into their embedding representations using the previously trained language model. Second, to improve the clustering process, the dimensionality of the generated embedding is reduced before clustering the documents using the Uniform Manifold Approximation and Projection (UMAP) technique. Third, the unsupervised machine learning clustering technique HDBSCAN. Finally, topic representations are obtained from the documents using a class-based TF-IDF (c-TF-IDF) variant.

This paper introduces an urgent students’ posts Topic Model (UPTM) based on Natural Language Processing (NLP) and the BERTopic modelling technique. We aim to identify and detect the cause of urgent posts based on spontaneous learners’ interactions in MOOCs discussion forums.

2 Previous work

Massive Open Online Courses (MOOCs) have become an increasingly popular mode of delivering higher education to large, geographically dispersed audiences (Chen 2014 ). A key component of the MOOC experience is the online discussion forums, which serve as a hub for student-student and student-instructor interactions (Kizilcec, Piech, and Schneider 2013 ).

Prior research has highlighted the importance of these forums in fostering a sense of community and social presence for MOOC learners, which in turn can positively impact student engagement, satisfaction, and learning outcomes (Wang and Baker 2018 ). For example, a study by (Gillani and Eynon 2014 ) found that students who actively participated in MOOC forums were more likely to complete the course and achieve better learning outcomes compared to their less engaged peers.

Furthermore, (Wang and Baker 2018 ) examined the relationship between student interactions in MOOC forums and their perceived sense of community and social presence. Their findings suggest that the quality and quantity of student-to-student and student-to-instructor interactions in the forums are key predictors of learners’ feelings of connectedness and belonging within the MOOC environment.

Recently (Wei et al. 2023 ) explored engagement strategies within MOOC forums, with a focus on low-achieving students. The findings revealed that low-scoring students who made significant progress tended to engage less in peer-peer and peer-teacher interactions. Instead, learner-content interactions emerged as crucial for advancing learning, acquiring new information, and enhancing linguistic knowledge. Quick feed- back and targeted suggestions were preferred over extensive peer discussions. The implications from this study underscore the importance of continuous teacher support and encouragement of peer-generated content.

Furthermore, (Bonafini et al. 2017 ) found that increased engagement in both forums and video content correlated positively with higher course achievement. Interestingly, the intention to certify played a moderating role in video consumption and overall achievement. These insights underscore the critical role that MOOC discussion forums play in shaping the overall learning experience and student success in these online learning platforms (Kizilcec, Piech, and Schneider 2013 ).

NLP holds immense potential for enhancing education, and its application in MOOCs continues to evolve. Researchers and practitioners alike are exploring novel ways to leverage NLP for better learning outcomes. NLP plays a crucial role in personalizing instructional materials for individual students. By analyzing web content, it tailors learning resources to student interests. Moreover, NLP assists in generating test questions for teachers and semi-automating educational technology systems. Recent phenomena like MOOCs have opened up new research opportunities, bridging the gap between NLP and education (C. Li and Xing 2021 ; Wu et al. 2024 ). Furthermore, Advanced Natural Language Processing (NLP) significantly contributes to the analysis of educational data. Researchers have delved into diverse aspects, encompassing sentiment annotations, entity annotations, text summarization, and topic modeling (Shaik et al. 2022 ).

In MOOCs, topic modeling has been used to analyze student behavior, identify popular topics, and improve course design. Different studies utilized topic modeling to identify topics of interest based on MOOCs reviews. The authors of (Peng et al. 2016 ) suggested a Like-Latent Dirichlet Allocation (Like-LDA) model that uses the behavioral characteristic "like" to create a profile of learner topic interest. (S. Liu et al. 2017 ) Suggested an author-topic model based on an unsupervised learning concept to extract learning topics for each learner. Their study aimed to analyze and focus on learners’ interests to facilitate further personalized course recommendations based on topic information hidden in the review data in MOOCs.

The study of (Vytasek, Alyssa F Wise, and Woloshen 2017 ) explores four potential methods for using topic modeling to help instructors manage and organize MOOCs discussion forums. Different approaches were proposed for topic modeling, from tra- ditional algorithms to the most recent deep learning-based methods. (Ramesh et al. 2014 ) built a topic model using LDA to detect latent topics in students’ writings in forum discussions to predict student retention in MOOCs. The authors (Lubis, Rosmansyah, and Supangkat 2019 ), developed a topic model using LDA, sentiment analysis and a sentence filtering approach based on helpful subjective posts in MOOCs. The work in (B. Yang et al. 2022 ) used latent semantic analysis (LSI) to classify and identify learners with distinct longitudinal profiles of topic-relevant forum posting in MOOCs. The work of (Bafna and Saini 2020 ) compared various topic modeling techniques including LDA, LSI, and NMF on MOOCs discussion forums data. (B. Yang et al. 2022 ) proposed a hierarchical NMF-based framework for topic modeling in MOOCs. Their framework not only identified topics at different levels of granularity but also helped to understand the relationships between topics.

Pre-trained word embeddings have dominated the semantic representation space since they were first developed. Pre-trained word embeddings, such as Word2vec and GloVe, on the other hand, compute a single static representation for each word. This, in turn, results in disregarding the significance of context in illuminating the precise meanings of words (Camacho-Collados and Pilehvar 2020 ). Most recent research in natural language processing has been interested in pre-trained transformer-based lan- guage models like BERTs (Terragni et al. 2021 ; Zhao et al. 2021 ). (Bianchi, Terragni, and Hovy 2020 ) suggested using Sentence-BERT to generate the document embed- ding vectors instead of bag-of-words (BoW) representations. Their results showed that context document embeddings produce significantly more coherent topics than BoW representations. Mueller and Dredze extended this approach (Mueller and Dredze 2021 ) who also considered fine-tuning the representations. (Hoyle, Goel, and Resnik 2020 ) follow a similar direction and use knowledge distillation to combine neural topic models and pre-trained transformers (Zhou and Wakabayashi 2022 ). Proposed a jointly fine-tuned BERT model for phrase and sentence embeddings and utilized it on a phrase-level topic model. According to their experiments, the model could generate well-performed phrase-level topics.

Recently, a growing interest has been in leveraging BERT-based models for topic modeling in MOOCs. These research works utilize BERT’s contextual embeddings to improve the accuracy and effectiveness of topic extraction from MOOCs text data. (Najmani et al. 2023 ) utilized Topic modeling to identify subjects that may interest learners within MOOC courses and, more broadly, to uncover latent themes within unstructured text collections without needing specific training data. BERTtopic were used in the work of (Zankadi et al. 2023 ) to extract topics of interest from the text content submitted by learners to enrich their course preferences in MOOCs. The authors (ibid.) extract the topical interest from the text content shared by learners on social media to enrich their course preferences in MOOCs. They applied NLP and topic modeling techniques using different traditional topic models approaches and BERTopic. Their results have demonstrated that BERTopic outperformed the other models. Other studies have explored hierarchical topic modeling frameworks, such as (Meng et al. 2020 ), and joint models that combine document classification and topic modeling in MOOC contexts.

3 Topic modeling for urgent posts

The nature of urgent posts requiring instructors’ attention can vary depending on learners’ specific challenges. These challenges can be specific to the course, such as difficulties in understanding certain materials, or they can encompass broader issues like logistical or technological problems related to downloading videos, accessing YouTube and, file loading. Recognizing the topics associated with urgent posts allows instructors to address them with greater specialization and professionalism.

For this study, a range of topic modeling techniques, including LDA, LSI, NMF, and BERTopic, were employed to identify the topics discussed in learners’ urgent posts. Utilizing these approaches aimed to gain insights into the underlying themes and subjects that emerge from the urgent posts. This information can inform instructors’ responses and interventions, enabling them to support the learners better.

A series of preprocessing techniques are applied to prepare the textual data from the learners’ posts. Subsequently, feature extraction is done on the data using LDA, LSI, and NMF techniques. The prepared textual data is then used to train four topic modeling techniques: LDA, LSA, NMF, and BERTopic. The performance of these techniques is evaluated using topic evaluation metrics, such as Coherence metrics score and Inverted Rank-Biased Overlap (RBO) score. The following sections provide comprehensive details about the data and the step-by-step process of extracting topics using automated topic modeling approaches.

3.1 Data set

We conducted our experiments using the Stanford MOOC Posts dataset (A. Agrawal and Paepcke 2014 ), which consists of 29,590 learner forum posts from eleven Stanford University public online courses. The dataset encompasses courses from three domains, namely Education, Humanities, and Medicine, with an equal distribution of courses from each domain. Table 1 illustrates the distribution of courses within each domain.

Table 2 presents a sample of frames from the Stanford MOOCs posts dataset, showcasing manual labeling that includes urgency scores for different types of courses. The figure highlights the diverse causes of urgency for the posts. For instance, the last post’s urgency is attributed to quiz issues, while the first and second posts are related to problems with downloading videos and accessing YouTube. This variation in the topics or causes of students’ urgent posts underscores the importance of topic modeling in identifying and directing these topics to the relevant individuals responsible for addressing such issues.

The Stanford MOOCs Posts dataset has undergone manual labeling, encompassing various dimensions, one of which is urgency. The urgency dimension is rated on a scale ranging from 1 to 7. A post assigned a rank of 1 indicates that it is not urgent and does not require an immediate response from the instructor. On the other hand, a post assigned a rank of 7 signifies that it is of utmost importance and demands the instructor’s immediate attention.

For this study, only posts with a rank above four are considered urgent and included in the dataset for model training. After applying this criterion, a total of 6,415 posts were obtained. Table 3 provides an overview of the distribution of posts across different types of courses.

By employing this binary classification approach, it is found that urgent posts account for approximately 20% of all posts across the various domains. This relatively small percentage of critical cases significantly reduces the instructor’s workload, as they only need to focus on tracking and responding promptly to the urgent posts, while the non-urgent posts make up the remaining 80% of the workload.

To assess the effectiveness of various topic modeling techniques, we will utilize students’ posts labeled as urgent as our reference datasets. These urgent posts are distributed across different types of courses, necessitating experiments on different subsets of the dataset. The dataset will be divided into four distinct groups, namely Group A, Group B, Group C, and Group D, based on the course types.

Group A includes all urgent posts from the dataset, regardless of the course type.

Group B includes only urgent posts from the Education course type.

Group C includes only urgent posts from the Humanities course type.

Group D includes only urgent posts from the Medicine course type.

By partitioning the dataset in this manner, we can evaluate the performance of the topic modeling techniques on specific subsets of urgent posts, allowing for a more targeted analysis based on course types.

3.2 Data preprocessing

Text preprocessing is crucial for cleaning and preparing text data before feeding it into a model. Several preprocessing tasks are applied, including text cleaning, tokenization, stop word removal, and part-of-speech tagging.

The first step involves converting reductions, such as "won’t" and "can’t," into their natural forms to improve clarity. Next, the data is cleaned by removing links, numbers, emojis, special characters, punctuation, and excess spaces. Additionally, commonly used words like "a," "an," "the," and others are eliminated. The NLTK library utilizes a predefined list of stop words. The specific version of NLTK used in this context is 3.8.1. This list comprises frequently occurring words that typically carry little semantic weight and can be safely removed from the text.

In addition, all characters in the text were converted to lowercase. NLTK package contains classes and interfaces for part-of-speech tagging, or simply “tagging”. NLTK tagging was employed, and only nouns, adjectives, verbs, and adverbs were retained. Subsequently, the text underwent tokenization, splitting the sentences into individual words.

3.3 Experimental setup

After the preprocessing phase, the feature extraction stage was carried out. In this stage, the data needs to be converted into a numerical form that can be understood by machine learning algorithms. This involves transforming the text documents into vector representations, where each post represents one document. The transformation process can be classified into two categories based on the adopted topic modeling techniques: Bag of Words transformation and sentence transformer embedding model. These techniques enable converting textual data into numerical representations suitable for further analysis and modeling.

The Bag of Words transformation is a feature extraction technique for the LDA, LSI, and NMF models. It represents a document data model that focuses on the occurrence of words within a document (Diera et al. 2022 ). A dictionary and a corpus need to be created to train these models. The dictionary captures the mapping between normalized words and their assigned integer IDs, while the corpus lists tuples for each word ID and its frequency within the document.

In natural language processing, there are two types of hyperparameters: latent topics and Dirichlet priors. The LDA, NMF, and LSI models utilize latent topics as hyperparameters. On the other hand, Dirichlet priors (alpha and beta) are specifically used for the LDA model. Typically, the alpha and beta values are set to "Auto," allowing the model to learn the optimal values for these parameters during execution.

Determining the number of latent topics before running the LDA, NMF, and LSI models is important. A grid search approach was employed to find the optimal number of topics for these models, and this process will be detailed in the evaluation section. For BERTopic, the sentence transformer embedding model was utilized to convert the text data into numerical representations. Specifically, the "all-MiniLM-L6-v2" sentence-transformers model, designed for semantic similarity tasks, was employed.

This model has demonstrated strong performance across various applications.

To further process the numerical representations, the UMAP algorithm was employed. UMAP is the default dimensionality reduction technique used in BERTopic. It helps reduce the dimensionality of the numerical representations, making them more manageable and suitable for subsequent analysis.

Reducing the dimensionality of a dataset is crucial for identifying groups of documents with similar semantic properties. This reduction process helps preserve the dataset’s local and overall structure. In the UMAP dimensionality reduction technique, one of the hyperparameters is the number of nearby "n_neighbors" sample points used in the manifold approximation. Choosing smaller values for this parameter provides a more localized perspective of the embedding structure, while larger values offer a

To optimize the coherence values, different values for the "n_neighbors" parameter were tested. Setting it to 0.7 yielded the highest coherence values, indicating an optimal balance for the dataset. Another important hyperparameter in UMAP is "n_components," which defines the reduced dimensions of the embeddings. The default value for "n_components" is set to 5, aiming to minimize dimensionality while maximizing the information captured in the generated embeddings. Genrally we we optimized hyperparameters such as UMAP’s n_neighbors and BERTopic’s n_components by testing different values against coherence scores. We selected the values that achieved the highest coherence scores.

The remaining UMAP parameters were set to their default values. "calculate probabilities" was set to “True”, determining the likelihood that a document belongs to any given topic. The number of topics was set to "auto," allowing the algorithm to determine the optimal number automatically. The minimum distance parameter was set to 0.05, indicating the minimum acceptable separation between points in the reduced-dimensional space. The metric used for distance calculation was set to "cosine," which measures the angular similarity between vectors. The random state was set to "100" to ensure reproducibility of the results.

Two important components in BERTopic that are often overlooked are the CountVectorizer and cTFIDF computation. These components play a crucial role in constructing the topic representations and offer flexibility for customization. The CountVectorizer has various settings that can be adjusted to enhance the quality of the topic representations. For example, the "ngram_range" option allows choosing the number of tokens in each entity within a topic representation.

In BERTopic, TFIDF is modified to work on a cluster/categorical/topic level rather than a document level. This modified version, cTFIDF, considers the distinctions between documents in different clusters, providing a more accurate representation of topics derived from the bagofwords matrix.

3.4 Topic identification with BERTopic Model

BERTopic is an advanced approach to topic modeling that incorporates BERT embeddings and c-TF-IDF. It produces concise and well-defined clusters, making it easier to interpret the topics. BERTopic ensures that important words are preserved in the topic descriptions, enhancing the quality of the generated topics. One of the key features of BERTopic is its ability to extract coherent topic representations. It achieves this by utilizing a modified version of TF-IDF, known as c-TF-IDF, which considers class information and improves the clustering process.

BERTopic also automatically determines the number of topics, saving the user from manually specifying this parameter. It provides convenient visualization options to explore and understand the generated topics effectively. In addition, BERTopic offers support for various topic modeling variations, including class-based topic modeling, which considers class labels during the modeling process. It also enables hierarchical topic reduction, resulting in a more organized and structured representation of topics. Moving on to applying BERTopic in all dataset groups, let’s focus on group A. Using the setting shown in Table 4 , we obtained 57 automatically generated topics. Figure 1 provides a visualization of the topic word scores for the first eight topics within this group. Certain topics, like topics 1,3, and 4, are directly related to the course material. On the other hand, there are general topics, such as topics 0, 2, and 6, which cover subjects like essays, questions and technological issues, including downloading videos.

Part of topic word scores for dataset group A

3.5 Practical Applications of Proposed Algorithms in Educational Contexts

To give concrete examples of how the proposed algorithms can be applied in educational settings. We used the trained BERTopic model to predict the main topics of urgent posts. Table 5 shows examples of the topics expected in learners’ urgent posts. We can notice that topic 0 is related to the essay which is a general topic in all training courses. We also notice the different cases related to it, such as: How will articles be received, formatted, and calibrated. Topic 1 is associated with humanities and medicine course materials, covering discussions related to cold and temperature. The second topic primarily revolves around videos, downloads, and slides. It also en-compasses various related issues, such as very short videos, indicating video runtimes, and the necessity for downloadable videos in countries with blocked websites.

Such example highlighted the varying critical topics among students, emphasizing the need for specialized approaches to address them. There are two main categories: content-specific issues, which subject teachers address, and general problems like technical issues and Inquire and follow up on required assignments.

By addressing various critical aspects, we can save the teacher’s time by focusing on subject-related concerns and topics that raise questions or cause confusion. General problems can be handled by specialists. Recognizing the cause of urgent forum posts and dealing with them through specialists allows for prompt feedback, which enhances students’ motivation by providing timely recognition and guidance, fostering a sense of achievement and progress (Shanshan and Wenfei 2024 ). Additionally, it reduces anxiety by clarifying doubts and offering support, creating a more secure learning environment (ibid.). Moreover, prompt responses contribute to a sense of community within the course, encouraging interaction and engagement among peers and instructors (H.-H. Yang and Lin 2023 ). These psychological benefits are crucial for improving student retention and success in MOOCs.

3.6 Using BERTopic across different course domains

BERTopic offers the flexibility to apply class-based topic modeling, which we utilized in the context of different course types, namely Medicine, Education, and Humanities. Figure 2 illustrates the results of this analysis. Upon examination, it is noticeable that topics 0, 2, and 8 are general topics that appear across all training courses and are not specifically related to the course content. Conversely, topics related to the course content are not spread across multiple courses and are more distinct to each course type. This demonstrates how class-based BERTopic modeling can be applied across various course domains, effectively handling a wide range of subjects, languages, and cultural contexts.

Topics per course type

To delve deeper into further analysis, we extended our investigation to the other dataset groups: B, C, and D. In group B, we obtained eight automatically generated topics, while group C yielded seventeen topics, and group D resulted in thirty-seven topics. For a visual representation of these topics, please refer to Figs. 3 , 4 , and 5 , which display the visualizations of the topic word scores for each respective dataset group.

Topic word scores for Dataset group B

Topic word scores for Dataset group C

Topic word scores for Dataset group D

4 BERTopic Comparative analysis with traditional models

We comprehensively evaluated and compared BERTopic and traditional topic models, mainly LDA, LSI, and NMF. The experiments were applied across the four dataset groups: A, B, C, and D. To assess their effectiveness, we utilized two metrics: Coherence metrics score and Inverted Rank-Biased Overlap (RBO) score. Topic Coherence is a metric that measures the quality of an individual topic by quantifying the semantic similarity between highly relevant words within the topic. It helps distinguish between topics that exhibit semantic coherence and those merely statistical artefacts. One commonly used coherence metric is CV, which constructs content vectors based on word co-occurrences and calculates the score using normalized pointwise mutual information (NPMI) and cosine similarity. The coherence score ranges from 0 to 1, with higher values indicating better coherence.

The Inverted Rank-Biased Overlap (IRBO) score evaluates the diversity of topics generated by a particular model. It compares the top N words of two topics and utilizes weighted ranking. A diversity score of 0 suggests redundant topics, while scores closer to 1 indicate greater topic variation. Higher values for both metrics indicate better performance (Murakami, Itsubo, and Kuriyama 2022 ). By analysing these metrics, we can accurately evaluate the effectiveness of different topic models and identify the models that produce topics with higher levels of coherence and diversity.

The selected approach for determining the optimal number of topics in LDA, LSI, and NMF models involves constructing multiple models with different values for the number of topics (k). The model with the highest coherence score indicates the significance of the generated topics. The process begins with a range of values for the number of topics, typically starting from two and incrementing by two. Only the number of topics is varied as a hyperparameter while keeping other parameters constant until the highest coherence score is achieved. This experiment is conducted across different dataset groups (A, B, C, and D).

Figures 6 , 7 , 8 , and 9 display the coherence scores corresponding to the number of topics for the different dataset groups’ LDA, LSI, and NMF models. The optimal number of topics for each model is determined by the highest coherence score, indicating the relevance and significance of the topics. In the case of the BERTopic model, the training process results in 50 topics with a coherence score of 0.616 for dataset group A.

Optimal number of topics for LDA, LSI, NMF and BERTopic for Group A

Optimal number of topics for LDA, LSI, NMF and BERTopic for Group B

Optimal number of topics for LDA, LSI, NMF and BERTopic for Group C

Optimal number of topics for LDA, LSI, NMF, and BERTopic for Group D

Table 6 presents the optimal number of topics, their corresponding coherence scores for each model for dataset group A, and the IRBO values. For dataset groups B, C, and D, Tables 7 , 8 , and 9 indicate the optimal numbers of topics determined by the highest coherence scores for the traditional models, and the number of topics automatically obtained using the BERTopic model. These tables also include the IRBO values for evaluation.

The findings in Tables 6 , 7 , 8 and 9 demonstrate the coherence scores obtained by different topic modeling techniques. For dataset group A, the best coherence score achieved by LDA was 0.542, while the worst was 0.363 for dataset group B. Regarding LSI, the highest coherence score of 0.5117 was observed for dataset group B, whereas the lowest score of 0.55 was recorded for dataset group C. Regarding NMF, the best coherence score of 0.755 was obtained for dataset group D, while the worst score of 0.620 was observed for dataset group B. Lastly, BERTopic achieved a coherence score of 0.689, the highest for dataset group C, while the lowest score of 0.604 was recorded for dataset group D.

It is evident from these results that NMF and BERTopic models exhibit higher coherence scores compared to LDA and LSI. The BERTopic model achieved coherence scores of 0.616, 0.638, 0.689, 0.611, and 0.604 when utilizing 50, 10, 17, and 37 topics for dataset groups A, B, C, and D, respectively. Similarly, the NMF model obtained coherence scores of 0.66, 0.62, 0.658, and 0.755 when employing 6, 4, 8, and 6 topics for dataset groups A, B, C, and D, respectively. Additionally, both models demonstrated nearly identical high scores close to one for the IRBO metric.

5 Discussion

This study aims to predict the reasons behind learners’ urgent posts on MOOC forums by analyzing the textual content they share. To achieve this goal, a comparison was made between BERTopic and various traditional topic models, including LDA, LSI, and NMF.

For training LDA, LSI, and NMF models, a bag-of-words (BoW) corpus was utilized, while BERTopic employed a pre-trained sentence transformer model known as "all-MiniLM-L6-v2". The quality and relevance of the generated course topics across the dataset were evaluated using coherence and RBO scores.

To assess different topic modeling approaches, the reference dataset consisted of student postings labeled as urgent. These urgent postings represented various course types, making the reference dataset representative of various courses. Consequently, experiments were conducted on different subsets of the dataset, with the dataset being divided into four groups: A, B, C, and D, based on the course types they corresponded to.

The LDA, LSI, NMF, and BERTopic models were applied to all dataset groups, yielding notable results. Group A’s coherence scores were 0.542, 0.459, 0.66, and 0.616, respectively, while the RBO scores were 0.974, 0.914, 1, and 1. Similarly, the other subset dataset groups exhibited promising coherence and RBO scores, as indicated in Tables 6 , 7 , 8 , and 9 .

Upon examining the graphs presented in Figs. 6 , 7 , 8 , and 9 the results provided in Tables 6 , 7 , 8 , and 9 , it becomes evident that the NMF and BERTopic models exhibited superior performance compared to the other models. The NMF model demonstrated better performance with a small number of topics, whereas the BERTopic model automatically generating the best number of topics with higher levels of coherence.

It is observed from the results that the number of topics generated automatically by the BERTopic model is generally greater than the optimal number of topics produced by other models. The results obtained demonstrated the ability of BERTopic to distinguish and extract diverse topics comprehensively and coherently, facilitating the identification of various reasons behind MOOC forum posts. A larger number of topics indicates a higher level of specificity, as the model considers more detailed information within the data context. Conversely, a smaller number of topics suggests a reduced level of detail.

We employed the trained BERTopic model to identify the primary topics in urgent posts. Table 5 provides illustrative examples of the topics commonly found in learners’ urgent inquiries. Leveraging the trained BERTopic model for topic prediction can substantially improve the responsiveness and relevance of a chatbot specifically designed to address urgent posts.

While BERTopic models demonstrate superior performance, there are potential limitations to consider. Firstly, the computational demands of BERT models can pose challenges for users with limited computational resources or when handling large datasets. Secondly, biases in language understanding may arise, as BERT models can inherit biases from their training data, potentially skewing topic representations. Additionally, the scalability of BERTopic in environments with limited computational resources, such as MOOC platforms with thousands of concurrent users, needs to be addressed. A statistical significance analysis between model performances could further enhance the study.

6 Conclusion

MOOCs face challenges such as low completion rates and high dropout rates. The limited number of instructors compared to many learners contributes to a lack of interaction and timely response to urgent posts from learners. Previous research on urgent posts has focused on identifying them without delving into their underlying causes. This study, however, breaks new ground by examining the causes of urgent posts using topic modeling techniques to predict their root causes automatically.

To accomplish this, the researchers employed four well-established models: LDA, LSI, NMF with BOW corpora, and BERTopic with sentence embeddings. Before training the models, a natural language processing (NLP) pipeline is applied for data cleaning and preprocessing. The models were evaluated using coherence and RBO scores, assessing the generated topics’ quality and diversity.

Based on the experimental results, it was observed that the NMF and BERTopic models achieved better performance compared to the other models. The NMF model exhibited superior results when a smaller number of topics was utilized, whereas the BERTopic model excelled in generating topics with higher levels of coherence when a larger number of topics was required.

Automatic classification of urgent posts and automatic prediction of their causes help to deal with those causes more professionally and specialized. This facilitates the instructors of a recommendation system that considers learners’ problems and then directs course administrators to address them. Or build a chatbot to help students solve their urgent problems personally. In addition, we aspire to evaluate our approach to MOOCs to highlight the multiple problems and their causes and deal with them automatically in MOOCs.

The automated classification of urgent posts and the subsequent prediction of their causes contribute to a more professional and specialized approach to addressing these underlying issues. This, in turn, facilitates the implementation of various solutions in the context of MOOCs. For instance, it enables the development of a recommendation system that considers learners’ problems and directs course administrators to address them effectively. Alternatively, it allows for the creation of a chatbot that can personally assist students in resolving their urgent problems.

Furthermore, our approach to evaluating MOOCs aims to shed light on the multiple problems and their respective causes and to automate the process of addressing them within the MOOC environment. By employing automated techniques, we aspire to enhance the overall experience of learners and instructors by efficiently identifying and resolving these issues promptly.

7 Future work

While the study has provided insights into topic modeling in the context of MOOC platforms, with the aim of investigating the reasons behind urgent posts in MOOC forums, there are several potential directions for future research.

These directions aim to expand and improve the current understanding of topic modeling techniques Large Language Models (LLMs), as well as validate the generalizability of the results across different platforms and developing new evaluation metrics that can assess the generated topics.

Fine-tuning LLMs for MOOC-specific tasks holds significant promise. Recent research trends emphasize the need to adapt LLMs effectively to enhance learning outcomes. For instance, (Wei et al. 2023 ) explored the use of deep-learning-based natural language generation (NLG) models to provide personalized support in MOOC discussion forums, bridging the gap between human-generated and automated responses.

To verify the generality of the results obtained from the current study, it is essential to extend the research to other MOOC platforms. While the findings from the current study provide insights into topic modeling within a specific platform, the landscape of MOOC platforms is diverse, with variations in course topics, learner demographics, and platform features. Conducting similar studies on different MOOC platforms can help evaluate the generalizability of the identified topics and uncover platform-specific variations. Moreover, comparing the results across multiple platforms will contribute to a more comprehensive understanding of the topics prevalent in the MOOC domain. In addition, conducting comparative studies with other educational platforms, such as Learning Management Systems (LMS) or online discussion boards in traditional classrooms, can be beneficial.

Another aspect that warrants attention in future research is the evaluation of topic modeling performance. While the current study focused on topic extraction and interpretation, it is important to develop robust evaluation metrics that can quantitatively assess the quality and coherence of the generated topics. Exploring new evaluation techniques and metrics specific to MOOC platforms can contribute to a more rigorous assessment of topic modeling algorithms.

By exploring these future research directions, the field can advance our understanding of the underlying reasons behind urgent posts in MOOC forums, leading to more effective interventions, enhanced learner support, and improved course completion rates.

Data availability

We conducted our experiments using the Stanford MOOC Posts dataset (A. Agrawal and Paepcke 2014 ). It is available on demand at the link https://datastage.stanford.edu/StanfordMoocPosts/.

Abdelrazek, Aly, Yomna Eid, Eman Gawish, Walaa Medhat, and Ahmed Hassan (2023). “Topic modeling algorithms and applications: A survey”. In: Information Systems 112, p. 102131.

Agrawal, A. and A. Paepcke (2014). The Stanford MOOCPosts Data Set . figshare https://datastage.stanford.edu/StanfordMoocPosts/ .

Agrawal, Akshay, Jagadish Venkatraman, Shane Leonard, and Andreas Paepcke (2015). “YouEDU: Addressing Confusion in MOOC Discussion Forums by Recommending Instructional Video Clips.” In: International Educational Data Mining Society .

Almatrafi, Omaima, Johri, Aditya, & Rangwala, Huzefa. (2018). Needle in a haystack: Identifying learner posts that require urgent response in MOOC discussion forums. Computers & Education, 118 , 1–9.

Google Scholar  

Alrajhi, Laila and Alexandra I Cristea (2023). “Plug & Play with Deep Neural Networks: Classifying Posts that Need Urgent Intervention in MOOCs”. In: International Conference on Intelligent Tutoring Systems . Springer, pp. 651–666.

Angelov, Dimo (2020). “Top2vec: Distributed representations of topics”. In: arXiv preprint arXiv:2008.09470 .

Arora, Sanjeev, Rong Ge, Ravindran Kannan, and Ankur Moitra (2012). “Computing a nonnegative matrix factorization–provably”. In: Proceedings of the forty-fourth annual ACM symposium on Theory of computing , pp. 145–162.

Bafna, Prafulla B and Jatinderkumar R Saini (2020). “On exhaustive evaluation of eager machine learning algorithms for classification of Hindi verses”. In: International Journal of Advanced Computer Science and Applications 11.2.

Bates, AT (2015). “Teaching in a digital age teaching in a digital age”. In: Creative Commons Attributions Non-Commercial International License .

Bianchi, Federico, Silvia Terragni, and Dirk Hovy (2020). “Pre-training is a hot topic: Contextualized document embeddings improve topic coherence”. In: arXiv preprint arXiv:2004.03974 .

Blei, David M, Andrew Y Ng, and Michael I Jordan (2003). “Latent dirichlet allocation”. In: Journal of machine Learning research 3.Jan, pp. 993–1022.

Blei, DM (2001). “Latent Dirichlet Allocation, Advances in Neural Information Processign Systems”. In: NIPS’01 .

Bonafini, Fernanda, Chungil Chae, Eunsung Park, and Kathryn Jablokow (2017). “How much does student engagement with videos and forums in a MOOC affect their achievement?” In: Online Learning Journal 21.4.

Bozkurt, Aras and Ramesh C Sharma (2020). “Emergency remote teaching in a time of global crisis due to CoronaVirus pandemic”. In: Asian journal of distance education 15.1, pp. i–vi.

Camacho-Collados, Jose and Mohammad Taher Pilehvar (2020). “Embeddings in natural language processing”. In: Proceedings of the 28th international conference on computational linguistics: tutorial abstracts , pp. 10–15.

Chen, Sue-Jen (2014). “Instructional design strategies for intensive online courses: An objectivist-constructivist blended approach.” In: Journal of interactive online learning 13.1.

Devlin, Jacob, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova (2018). “Bert: Pre-training of deep bidirectional transformers for language understanding”. In: arXiv preprint arXiv:1810.04805 .

Dhawan, Shivangi (2020). “Online learning: A panacea in the time of COVID-19 crisis”. In: Journal of educational technology systems 49.1, pp. 5–22.

Diera, Andor, Bao Xin Lin, Bhakti Khera, Tim Meuser, Tushar Singhal, Lukas Galke, and Ansgar Scherp (2022). “Bag-of-words vs. sequence vs. graph vs. hierarchy for single-and multi-label text classification”. In: arXiv preprint arXiv:2204.03954 .

Dumais, Susan (1994). “Latent semantic indexing (LSI) and TREC-2”. In: Nist Special Publication Sp , pp. 105–105.

El-Rashidy, Mohamed A, Nabila A Khodeir, Ahmed Farouk, Heba K Aslan, and Nawal A El-Fishawy (2024). “Attention-based contextual local and global features for ur- gent posts classification in MOOCs discussion forums”. In: Ain Shams Engineering Journal 15.4, p. 102605.

Gillani, Nabeel, & Eynon, Rebecca. (2014). Communication patterns in massively open online courses. The Internet and Higher Education, 23 , 18–26.

Grootendorst, M. (2022). “BERTopic: Neural topic modeling with a class-based TF-IDF procedure”. In: arXiv preprint arXiv:2203.05794 .

Guo, Yunyan and Jianzhong Li (2021). “Distributed Latent Dirichlet Allocation on Streams”. In: ACM Transactions on Knowledge Discovery from Data (TKDD) 16.1, pp. 1–20.

Hodges, Charles, Stephanie Moore, Barb Lockee, Torrey Trust, and Aaron Bond (2020). The difference between emergency remote teaching and online learning.

Hoyle, Alexander, Pranav Goel, and Philip Resnik (2020). “Improving neural topic models using knowledge distillation”. In: arXiv preprint arXiv:2010.02377 .

Jacobsen, Dan Yngve (2019). “Dropping out or dropping in? A connectivist approach to understanding participants’ strategies in an e-learning MOOC pilot”. In: Technology, Knowledge and Learning 24.1, pp. 1–21.

Jelodar, Hamed, Wang, Yongli, Yuan, Chi, Feng, Xia, Jiang, Xiahui, Li, Yanchao, & Zhao, Liang. (2019). Latent Dirichlet allocation (LDA) and topic modeling: models, applications, a survey. Multimedia Tools and Applications, 78 , 15169–15211.

Khodeir, Nabila A. (2021). Bi-GRU urgent classification for MOOC discussion forums based on BERT. IEEE Access, 9 , 58243–58255.

Kizilcec, René F, Chris Piech, and Emily Schneider (2013). “Deconstructing dis-engagement: analyzing learner subpopulations in massive open online courses”. In: Proceedings of the third international conference on learning analytics and knowledge , pp. 170–179.

Kontostathis, April and William M Pottenger (2006). “A framework for understanding Latent Semantic Indexing (LSI) performance”. In: Information Processing & Management 42.1, pp. 56–73.

Landauer, Thomas K, Peter W Foltz, and Darrell Laham (1998). “An introduction to latent semantic analysis”. In: Discourse processes 25.2-3, pp. 259–284.

Landauer, Thomas K, Danielle S McNamara, Simon Dennis, and Walter Kintsch (2013). Handbook of latent semantic analysis . Psychology Press.

Lee, Daniel D and H Sebastian Seung (1999). “Learning the parts of objects by non-negative matrix factorization”. In: Nature 401.6755, pp. 788–791.

Lee, Daniel and H Sebastian Seung (2000). “Algorithms for non-negative matrix factorization”. In: Advances in neural information processing systems 13.

Li, Chenglu, & Xing, Wanli. (2021). Natural language generation using deep learning to support MOOC learners. International Journal of Artificial Intelligence in Education, 31 , 186–214.

Liu, Sanya, Cheng Ni, Zhi Liu, Xian Peng, and Hercy NH Cheng (2017). “Mining individual learning topics in course reviews based on author topic model”. In: International Journal of Distance Education Technologies (IJDET) 15.3, pp. 1–14.

Lubis, Fetty Fitriyanti, Yusep Rosmansyah, and Suhono H Supangkat (2019). “Topic discovery of online course reviews using LDA with leveraging reviews helpfulness”. In: International Journal of Electrical and Computer Engineering 9.1, p. 426.

Meng, Yu, Yunyi Zhang, Jiaxin Huang, Yu Zhang, Chao Zhang, and Jiawei Han (2020). “Hierarchical topic mining via joint spherical tree and text embedding”. In: Proceedings of the 26th ACM SIGKDD international conference on knowledge discovery & data mining , pp. 1908–1917.

Mueller, Aaron and Mark Dredze (2021). “Fine-tuning encoders for improved mono-lingual and zero-shot polylingual neural topic modeling”. In: arXiv preprint arXiv:2104.05064 .

Murakami, Kayo, Norihiro Itsubo, and Koichi Kuriyama (2022). “Explaining the diverse values assigned to environmental benefits across countries”. In: Nature Sustainability 5.9, pp. 753–761.

Najmani, Kawtar, Lahbib Ajallouda, El Habib Benlahmar, Nawal Sael, and Ahmed Zellou (2023). “BERTopic and LDA, Which Topic Modeling Technique to Extract Relevant Topics from Videos in the Context of Massive Open Online Courses (MOOCs)?” In: International Conference on Digital Technologies and Applications . Springer, pp. 374–381.

Peng, Xian, Sanya Liu, Zhi Liu, Wenbin Gan, and Jianwen Sun (2016). “Mining learners’ topic interests in course reviews based on like-LDA model”. In: International Journal of Innovative Computing, Information and Control 12.6, pp. 2099–2110.

Ramesh, Arti, Dan Goldwasser, Bert Huang, Hal Daumé III, and Lise Getoor (2014). “Understanding MOOC discussion forums using seeded LDA”. In: Proceedings of the ninth workshop on innovative use of NLP for building educational applications , pp. 28–33.

Shaik, Thanveer, Tao, Xiaohui, Li, Yan, Dann, Christopher, McDonald, Jacquie, Redmond, Petrea, & Galligan, Linda. (2022). A review of the trends and challenges in adopting natural language processing methods for education feedback analysis. Ieee Access, 10 , 56720–56739.

Shanshan, Shang and Lyv Wenfei (2024). “Continuance intention to use MOOCs: The effects of psychological stimuli and emotions”. In: The Asia-Pacific Education Researcher 33.1, pp. 27–45.

Terragni, Silvia, Elisabetta Fersini, Bruno Giovanni Galuzzi, Pietro Tropeano, and Antonio Candelieri (2021). “OCTIS: Comparing and optimizing topic models is simple!” In: Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: System Demonstrations , pp. 263–270.

Trentin, Guglielmo (2000). “The quality-interactivity relationship in distance education”. In: Educational Technology , pp. 17–27.

Vytasek, Jovita M, Alyssa F Wise, and Sonya Woloshen (2017). “Topic models to support instructors in MOOC forums”. In: Proceedings of the seventh international learning analytics & knowledge conference , pp. 610–611.

Wang, Yuan and Ryan Baker (2018). “Grit and intention: Why do learners complete MOOCs?” In: International review of research in open and distributed learning 19.3.

Wei, Wei, Jia Liu, Xiaoshu Xu, Kimberly Kolletar-Zhu, and Yunfeng Zhang (2023). “Effective interactive engagement strategies for MOOC forum discussion: A self- efficacy perspective”. In: Plos one 18.11, e0293668.

Wise, Alyssa Friend, & Cui, Yi. (2018). Learning communities in the crowd: Characteristics of content related interactions and social relationships in MOOC discussion forums. Computers & education, 122 , 221–242.

Wu, Hao, Shan Li, Ying Gao, Jinta Weng, and Guozhu Ding (2024). “Natural language processing in educational research: The evolution of research topics”. In: Education and Information Technologies , pp. 1–27.

Xu, Wei, Xin Liu, and Yihong Gong (2003). “Document clustering based on non- negative matrix factorization”. In: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval , pp. 267–273.

Yang, Hsi-Hsun and Jia-Yu Lin (2023). “Students’ persistence intention in MOOCs in the psychomotor domain: An extended 3P model of the teaching and learning perspective”. In: Frontiers in Psychology 14, p. 1094138.

Yang, Bokai, Hengtao Tang, Ling Hao, and John R Rose (2022). “Untangling chaos in discussion forums: A temporal analysis of topic-relevant forum posts in MOOCs”. In: Computers & Education 178, p. 104402.

Zankadi, Hajar, Abdellah Idrissi, Najima Daoudi, and Imane Hilal (2023). “Identifying learners’ topical interests from social media content to enrich their course preferences in MOOCs using topic modeling and NLP techniques”. In: Education and Information Technologies 28.5, pp. 5567–5584.

Zawacki-Richter, Olaf (2021). “The current state and impact of Covid-19 on digital higher education in Germany”. In: Human Behavior and Emerging Technologies 3.1, pp. 218–226.

Zhao, He, Dinh Phung, Viet Huynh, Yuan Jin, Lan Du, and Wray Buntine (2021). “Topic modelling meets deep neural networks: A survey”. In: arXiv preprint arXiv:2103.00498 .

Zhou, Zikai and Kei Wakabayashi (2022). “Topic Modeling using Jointly Fine-tuned BERT for Phrases and Sentences”. In: The 14th Forum on Data Engineering and Information Management .

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Khodeir, N., Elghannam, F. Efficient topic identification for urgent MOOC Forum posts using BERTopic and traditional topic modeling techniques. Educ Inf Technol (2024). https://doi.org/10.1007/s10639-024-13003-4

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Received : 26 November 2023

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DOI : https://doi.org/10.1007/s10639-024-13003-4

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