Theory gaps in Agriculture

Representative open questions

Showing 30 of 44 — one per source paper, highest-quality first.

• Development and research trends of stay-green biology in legumes: a bibliometric and visual analysis over three decades (2026) · doi

  Basic themes such as stay-green syndrome in the context of geminivirus and hemiptera alydidae pest resistance show foundational importance but lack cohesive conceptual development. The molecular basis linking stay-green phenotypes to disease and pest resistance mechanisms requires integrated transcriptomic and physiological investigation.

• Evaluation of the effects of hydrogel and glycine betaine application on growth, physiological characteristics and yield of peanut under water deficit (2026) · doi

  Although the study found that combined hydrogel and GB application produced more significant increases in peanut growth and yield than either treatment alone, the physiological basis for this synergistic interaction was not mechanistically explored. Research should investigate whether synergistic effects operate through improved osmolyte accumulation, enhanced ion homeostasis regulation, or better soil water availability when both amendments are applied simultaneously to peanut.

• Rapid fertilizer turnover and dominant soil N mineralization in a cool-climate vineyard revealed by 15N tracing, biological N availability, and N exposure (2026) · doi

  A severe overwinter frost between 2021 and 2022 caused 95% reproductive bud mortality and markedly altered soil N dynamics (20–26% increase in total N, 77–106% increase in biological N availability in 0–30 cm layer). Future studies should systematically investigate the mechanisms and magnitude of frost-induced root mortality, freeze-thaw cycle effects on N immobilization in microbial biomass, and sap bleeding contributions to labile N pools using 15N isotope tracing across multiple freeze-thaw cycles.

• Dynamic regulation of secondary metabolites and agarwood aroma compounds in Aquilaria sinensis by the endophytic fungus NSZJ-CX-22 revealed through metabolomics and GC–MS (2026) · doi

  Alkaloid biosynthesis pathways (represented by atherosperminine and ergometrine) showed consistently low enrichment and weak significance across all culture stages, yet specific alkaloid compounds were identified as top VIP differential metabolites in mid-late cultivation. The regulatory mechanisms controlling alkaloid biosynthesis activation despite low pathway enrichment scores require dedicated investigation.

• Deciphering Trichoderma viride-mediated cadmium stress alleviation in wheat: morphological, physiological and biochemical insights (2026) · doi

  Conflicting results exist regarding the effect of Trichoderma species on proline and glycine betaine accumulation during cadmium stress—T. viride increased these osmoregulatory components in wheat, while T. harzianum reduced proline levels in V. radiata; comparative mechanistic studies across different Trichoderma strains and host plant species are needed to clarify the strain-specific and species-specific responses.

• Integrating combining ability and multivariate analysis for the selection of superior tomato hybrids (2026) · doi

  Although fruit firmness exhibits significant GCA and high heritability, suggesting additive genetic control favorable for improvement, the relationship between cell wall composition, pectin metabolism, and additive effects has not been mechanistically validated in these specific tomato hybrids. Direct investigation of the biochemical basis of firmness inheritance in H17, H2, and H11 hybrids would strengthen breeding decisions.

• Soil and Environmental Chemistry: Exercises (2017) · doi

  The retardation factor estimation for Alachlor transport assumes linear partitioning behavior, but nonlinear isotherm behavior evident in Tables 17-18 at low dissolved concentrations (<0.07 mg·dm−3) suggests potential site-limited sorption mechanisms that are not accounted for in the standard retardation coefficient model applied to chloroacetanilide herbicides.

• Evaluación comparativa de frameworks de visión artificial para el conteo automatizado y monitoreo de especies menores en sistemas pecuarios (2026) · doi

  YOLOv12 and RT-DETRv2 are recent architectures (2024-2025) with limited scientific literature; the long-range attention mechanisms and transformer-based detection approaches need empirical validation specifically on minor species in high-density occlusion scenarios. Future studies should evaluate whether attention mechanisms generalize to guinea pig and rabbit detection with partial occlusion patterns.

• Foliar potassium–calcium nutrition enhances fruit yield, quality and mitigates cracking in guava (Psidium guajava L.) under humid subtropical conditions (2026) · doi

  Partial least squares regression revealed that K and Ca effects on fruit quality are largely mediated through leaf physiological traits rather than direct accumulation, but the specific biochemical pathways linking leaf chlorophyll concentration and leaf area to fruit pectin content and peel structural integrity in guava have not been mechanistically elucidated.

• Mastering feed efficiency for a sustainable operation in poultry industry (2026) · doi

  Understanding of host-microbiome interactions directly influencing nutrient utilization and feed efficiency in poultry under diverse production environments remains mechanistically unclear. Targeted nutritional and microbial interventions to consistently improve feed efficiency require deeper knowledge of how microbiota composition and function vary across different management systems and their specific interactions with genetics and diet.

• Soil Chemistry (2012) · doi

  The mechanisms by which liming agents such as CaCO3 improve soil structure beyond neutralization remain unclear. Future research should investigate the specific physicochemical pathways through which lime amendments alter soil aggregate stability, porosity, and water retention in acid soils across different soil types and pH ranges.

• Effect of Applying GA3 Treatment on Vitis vinifera Agronomical Traits and Embryo Germination Rate (2026) · doi

  The mechanism by which GA3 application induces early fruit set and cell expansion leading to berry size enlargement in 'Rizamat' cultivars has not been investigated at the cellular or hormonal level, particularly regarding interactions with other phytohormones during fruit development.

• Biodiminution of lithium in forest floor food webs (2026) · doi

  The study examines lithium biodiminution in forest floor food webs but does not specify quantitative thresholds for lithium concentration levels at which bioaccumulation becomes physiologically significant in arthropods and other detritivores. Future work should establish dose-response relationships for lithium uptake across different arthropod taxa in forest soil ecosystems.

• Performance of Spring Wheat Genotypes for Quality, Yield, and Related Reproductive Traits under Different Production Systems (2026) · doi

  The paper identifies that Radmira achieves superior protein and gluten content under high-intensive production due to strong nitrogen uptake efficiency, but does not characterize the specific physiological or genetic mechanisms driving differential nitrogen use efficiency among the three genotypes. Detailed investigations into nitrogen uptake kinetics, remobilization patterns, and genetic markers associated with nitrogen use efficiency in these cultivars are absent.

• Chemistry of the pedosphere (2012) · doi

  The selectivity constant (Kexchange) for ion exchange reactions is presented in Equation 6.24 using concentration-based expressions, but the paper does not explain how activity coefficients or ionic strength effects should be incorporated when applying this selectivity constant to heterogeneous soil solutions with varying osmotic potential.

• Comparative Effects of Different Light Intensities on Performance and Egg Quality in Japanese Quails (2026) · doi

  Gizzard weight percentage varied significantly across light treatments (3.75-4.58% at 10-25 lux), but the physiological explanation for this organ-specific response to light intensity in Japanese quails—whether related to digestive capacity, feed particle size processing, or metabolic efficiency—was not investigated.

• Comparative Effects of Organic and Inorganic Fertilizers on the Nutritional Profile and in Situ Digestibility of Alfalfa (Medicago sativa L.) in Cannulated Buffalo Bulls (2026) · doi

  The control treatment (T0) showed significantly lower digestibility and longer lag time; the mechanisms by which nitrogen deficiency reduces rumen microbial activity and increases lignification of alfalfa cell walls require investigation through analysis of cell wall composition (cellulose, hemicellulose, lignin fractions) rather than NDF/ADF alone.

• Influence of Wheat Bran, Maize Bran and Soya Hulls Supplementation on Milk Yield, Composition and Physiological Responses in Cholistani Cattle (2026) · doi

  The study tested soya hulls, wheat bran, and maize bran supplementation at only 25% inclusion level in Cholistani cattle diets. The mechanism by which soya hulls improve or depress milk yield remains unexplained, as Het-land et al. (2001) reported increased milk yield with higher SH levels but did not elucidate the physiological pathway, while Bergeron (2002) attributed decreased yield to low starch content without mechanistic validation.

• Shrub Age and Water Dynamics Influence Primary Production, Carbon, and Nitrogen Stocks in a Coastal Environment (2024) · doi

  The study does not quantify how vegetation-microclimate feedbacks specific to woody plant encroachment in the coastal setting alter soil organic carbon accumulation rates or modify the partitioning of water between differently sized shrubs and potential groundwater recharge.

• JA-mediated H2O2 and ABA signaling enhances root hydraulic conductance in cotton under partial root-zone irrigation (2026) · doi

  The proposed model identifies JA as a systemic master signal translocated from leaves to hydrated roots under PRI, but the specific mechanisms governing JA synthesis induction by signals from the drying root zone and its long-distance translocation remain uncharacterized. Direct measurement of JA biosynthesis regulation and xylem/phloem transport kinetics during the PRI cycle is needed to validate this leaf-to-root signaling pathway.

• Stabilization of Expansive Clay Using Calcium Lignosulfonate for Subgrade Application (2026) · doi

  While the optimum stabilizer content was determined at 4%, the mechanism of why excess chemical (beyond 4%) reduces CBR values is not fully explained.

• Remote Sensing for Within-Plot Soil Variability Assessment Using NDVI Dispersion Metrics (2026) · doi

  The first two principal components explained only 37.33% of the total variance, reflecting the complexity of the system and the diversity of variables considered, indicating that substantial unexplained variance remains in the relationships among soil properties, terrain attributes, and crop indicators.

• Phosphate-solubilizing inoculants induce stage-specific rhizosphere microbiome shifts and enhance chickpea symbiosis under low P availability (2026) · doi

  The mechanisms by which fungal diversity directly influences nodulation and N2 fixation efficiency require further mechanistic investigation beyond correlational observations.

• Biochar orchestrates coordinated soil-microbe-metabolite responses in acidifying paddy soils: evidence from a 5-year field study (2026) · doi

  The mechanisms by which specific metabolites (alisol B 23-acetate and galdosol) support plant growth, pathogen defense, or microbial signaling remain incompletely characterized and require further functional validation.

• Enhancing immunity: antioxidant and immunomodulatory properties of steam blanching-prepared turmeric (Curcuma domestica Val.) powder (2026) · doi

  While the paper notes that flavonoids and phenols inhibit S. aureus growth through enzyme disruption, the specific molecular mechanisms of how turmeric compounds modulate IL-1, IL-6, and IL-8 levels require further elucidation.

• Analysis and Prospect of AI's Participation in Greenhouse Environmental Regulation (2026) · doi

  For unexpected situations that are not stored and analyzed in the AI database, AI struggles to handle them correctly and promptly, not as well as experienced agricultural growers.

• Quantitative assessment of the most common mycotoxins found in commercial poultry feed (2024) · doi

  Rising temperatures, increased CO2 levels, and extreme weather events (droughts, heavy rains) favor the growth of mycotoxin-producing moulds, and mycotoxin prevalence is shifting geographically, indicating a need for further research on climate-related impacts on mycotoxin contamination.

• Effects of microtopography and moisture on peatland soil temperature regime (a case study of the ridge-hollow complex Mukhrino bog) (2026) · doi

  While the study identifies that southern hollows are 1-2°C warmer than northern hollows, likely due to greater water saturation, the specific mechanisms linking aspect, insolation, and differential warming in hollow complexes warrant further investigation.

• Comparing the effect of negative friction on the design bearing capacity of precast piles with different assumed embankment thicknesses (2026) · doi

  Studying a pile problem affected by negative friction is quite complex and depends on many interrelated factors (pile type, pile length, soil characteristics, weak soil layer thickness, embankment height, load), suggesting need for more comprehensive analytical frameworks.

• Comparative Efficacy and Economic Appraisal of Different Feeds in Sexed Broilers (2026) · doi

  The mechanisms underlying improved feed conversion ratios and body weight gains with high-density diets warrant further investigation at the physiological and metabolic levels.