The escalating challenges of climate change, soil degradation, and the need to ensure global food security are driving the transition towards more sustainable agricultural practices. Biostimulants, a diverse category of substances and microorganisms, have emerged as promising tools to enhance crop resilience, improve nutrient use efficiency (NUE), and support sustainable intensification. However, their widespread adoption is hampered by significant variability in efficacy and a lack of consensus on their optimal use. This comprehensive review synthesizes current scientific knowledge to critically evaluate the performance of biostimulants within sustainable agricultural systems. It aims to move beyond isolated case studies to provide a holistic analysis of their modes of action, efficacy under stress, and interactions with the environment. The analysis confirms that biostimulant efficacy is inherently context-dependent, governed by a complex interplay of biological, environmental, and management factors. Performance variability is explained by four core principles: the Limiting Factor Principle, the Biological Competition Axiom, the Stress Gradient Hypothesis, and the Formulation and Viability Imperative. A significant disconnect exists between promising controlled-environment studies and variable field results, highlighting the danger of extrapolating data without accounting for real-world agroecosystem complexity. Biostimulants are not universal solutions but are sophisticated tools whose value is realized through context-specific application. Their successful integration requires a precision-based approach aligned with specific agronomic challenges. We recommend that growers adopt diagnostic tools and on-farm trials, while producers must provide transparent multi-location field data and invest in advanced formulations. Future research must prioritize field validation, mechanistic studies using omics tools, and the development of crop-specific protocols and industry-wide standards to fully unlock the potential of biostimulants for building resilient and productive agricultural systems.

The escalating challenges of climate change, soil degradation, and the need to ensure global food secu-rity are driving the transition towards more sustainable agricultural practices. Biostimulants, a diverse cate-gory of substances and microorganisms, have emerged as promising tools to enhance crop resilience, improve nutrient use efficiency (NUE), and support sustainable intensification. However, their widespread adoption is hampered by significant variability in efficacy and a lack of consensus on their optimal use. This comprehensive review synthesizes current scientific knowledge to critically evaluate the performance of biostimulants within sustainable agricultural systems. It aims to move beyond isolated case studies to provide a holistic analysis of their modes of action, efficacy under stress, and interactions with the environment. The analysis confirms that biostimulant efficacy is inherently context-dependent, governed by a complex in-terplay of biological, environmental, and management factors. Performance variability is explained by four core principles: the Limiting Factor Principle, the Biological Competition Axiom, the Stress Gradient Hy-pothesis, and the Formulation and Viability Imperative. A significant disconnect exists between promising controlled-environment studies and variable field results, highlighting the danger of extrapolating data without accounting for real-world agroecosystem complexity. Biostimulants are not universal solutions but are sophisticated tools whose value is realized through context-specific application. Their successful integra-tion requires a precision-based approach aligned with specific agronomic challenges. We recommend that growers adopt diagnostic tools and on-farm trials, while producers must provide transparent multi-location field data and invest in advanced formulations. Future research must prioritize field-validation, mechanistic studies using omics tools, and the development of crop-specific protocols and industry-wide standards to fully unlock the potential of biostimulants for building resilient and productive agricultural systems.

Canola (Brassica napus L.) may diversify wheat‐based cropping systems in the Northern Great Plains. However, agronomic adaptability and stability of high‐yielding genotypes have not been widely evaluated over the diverse environmental conditions of South Dakota (SD). A 2‐year field experiment was conducted in two contrasting environments (Brookings—eastern SD and Pierre—Central SD) to evaluate genotypes (10 in 2019 and 12 in 2020) for days to 50% flower, lodging, pods plant⁻¹, seed yield, 1000‐seed weight, and yield stability. Seed yield for all genotypes in Brookings averaged 1961 and 1740 kg ha⁻¹, in 2019 and 2020, respectively, whereas at Pierre, yields averaged 1470 and 858 kg ha⁻¹. Seed oil concentration was greater at Brookings (456 and 406 g kg⁻¹ in 2019 and 2020, respectively) than at Pierre (356 g kg⁻¹ in 2019). The additive main effects and multiplicative interaction model (AMMI) evaluated eight genotypes across locations and years for genotype × environment (GE) interactions and stability. Environment was the most dominant cause of variation among genotypes, explaining 67.7%, 41.4%, and 45.7%, of the variations in pods plant⁻¹, 1000‐seed weight, and seed yield, respectively, whereas GE explained most of the remaining variation. A combination of AMMI‐1 biplots and AMMI stability values found variability in genotypic response to environments for seed yield suggesting cultivar recommendations should be environment specific.

Micronutrients, particularly boron (B), iron (Fe), manganese (Mn), and zinc (Zn), are pivotal for cotton (Gossypium spp.) growth, reproductive success, and fiber quality. However, their critical roles are often overlooked in fertility programs focused primarily on macronutrients. This review synthesizes recent advances in the physiological, molecular, and agronomic understanding of B, Fe, Mn, and Zn in cotton production. The overarching goal is to elucidate their impact on cotton nutrient use efficiency (NUE). Drawing from the peer-reviewed literature, we highlight how these micronutrients regulate essential processes, including photosynthesis, cell wall integrity, hormone signaling, and stress remediation. These processes directly influence root development, boll retention, and fiber quality. As a result, deficiencies in these micronutrients contribute to significant yield gaps even when macronutrients are sufficiently supplied. Key genes, including Boron Transporter 1 (BOR1), Iron-Regulated Transporter 1 (IRT1), Natural Resistance-Associated Macrophage Protein 1 (NRAMP1), Zinc-Regulated Transporter/Iron-Regulated Transporter-like Protein (ZIP), and Gossypium hirsutum Zinc/Iron-regulated transporter-like Protein 3 (GhZIP3), are crucial for mediating micronutrient uptake and homeostasis. These genes can be leveraged in breeding for high-yielding, nutrient-efficient cotton varieties. In addition to molecular hacks, advanced phenotyping technologies, such as unmanned aerial vehicles (UAVs) and single-cell RNA sequencing (scRNA-seq; a technology that measures gene expression at single-cell level, enabling the high-resolution analysis of cellular diversity and the identification of rare cell types), provide novel avenues for identifying nutrient-efficient genotypes and elucidating regulatory networks. Future research directions should include leveraging microRNAs, CRISPR-based gene editing, and precision nutrient management to enhance the use efficiency of B, Fe, Mn, and Zn. These approaches are essential for addressing environmental challenges and closing persistent yield gaps within sustainable cotton production systems.

Maize (corn) (Zea mays L.) yield is influenced by complex factors, including abiotic and biotic stress and inconsistent nutrient use efficiency, which challenge optimal yield. Standard management recommendations often fall short, prompting interest in intensive management strategies within an Adaptive Maize Management System (ACMS). To investigate this, we employed an addition/omission technique within a randomized complete block design (RCBD) to compare standard maize management recommendations with an intensive management protocol aimed at identifying yield-limiting factors. Our intensive management approach combined early-season biostimulant applications with mid-season supplementation of phosphorus (P), potassium (K), and nitrogen (N) at the V7 stage, followed by foliar fungicides and additional foliar N at the R1 stage. Field trials spanned five Virginia locations over 2022 and 2023 under both irrigated and non-irrigated conditions, yielding ten site-years of data. Analysis via ANOVA in JMP^® Version 18 with Dunnett’s test revealed that the intensive management approach significantly increased grain yield in 3 of 10 experiments. Under non-irrigated conditions, the intensive management practices averaged 5.9% higher yield than the standard management check. We observed a higher response to irrigation in standard management check (34%) than in intensive management check (8.9%). Site-specific irrigation impacts ranged from 14% to 61%. Results emphasize site-specific input recommendations for yield enhancement.

Salt-affected soil areas are increasing in the Northern Great Plains (NGP), with patches occurring in some of the most productive croplands. High electrical conductivity (EC) and sodium and/or sulfate concentrations of saline–sodic areas impede the growth and yield of ‘normal’ [corn (Zea mays)/soybean (Glycine max)] rotational crops, and more appropriate management systems are needed. Brassica spp. and amendment applications, such as biochar, may provide management alternatives for these areas. In two greenhouse studies, (1) 10 canola (Brassica napus) genotypes were evaluated for emergence in non-saline (EC_1:1 = 0.62 dS m⁻¹), moderately saline–sodic (EC = 5.17 dS m⁻¹), and highly saline–sodic (EC_1:1 = 8.47 dS m⁻¹) soils and (2) 10 canola genotypes and 3 other brassicas (Brassica juncea/B. oleracea) were evaluated for emergence and biomass in non-saline or moderately saline–sodic soils with or without two 5% biochar (hardwood or softwood) amendments. Canola emergence at 28 days after planting (DAP) in moderately and highly saline–sodic soils was less than 12% for most genotypes, although one had 37% emergence. The hardwood biochar improved Brassica spp. emergence (42%) from the moderately saline–sodic soil compared to non-amended soil (29%), although shoot biomass was similar among treatments at 60 DAP. These findings suggest that specific salt-tolerant Brassica spp. may be an alternative crop for NGP saline–sodic soil areas. Florida broadleaf mustard, typically used for forage, had the greatest emergence (52%) in the saline–sodic soil and may be a suitable cover crop for these areas. In addition, hardwood biochar applications may aid in plant establishment.