Abstract Current food production challenges of soil degradation, rising demand, and climate change require a more holistic approach to crop nutrition. Scalable, multi‐nutrient fertilizers that can enhance yield and reduce nutrient losses are a promising solution. Polyhalite is a natural mineral containing potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S) that has multiple agronomic benefits. The main objective of this study was to combine evidence from hundreds of trials across different soils, crop species, and environments to quantify the yield response to polyhalite. Factors affecting the yield response to polyhalite, including soil K and S availability and crop species, were investigated. To compare polyhalite's performance with conventional fertilizers, we contrasted the results of restricted maximum likelihood meta‐analysis, with and without the exclusion of outliers, with simpler comparisons of means and medians. The data included 921 replicated trials conducted on 47 crops across 33 countries over 10 years. Fertilizer programs based on polyhalite outperformed conventional fertilizers, with a 6.6% yield increase over nitrogen + phosphorus (NP) and 3.2% over nitrogen + phosphorus + potassium (NPK) controls for all the trials. For the trials that were responsive to K or S, this increase was 12.2% over NP and 4.8% over NPK controls. Polyhalite increased yields over NP control by 3.8%–16.3% across different crops, with the highest responses of 16.3% in sugarcane ( Saccharum officinarum L.), 12.5% in vegetables, and 9.5% in potatoes ( Solanum tuberosum L.). These results demonstrated polyhalite's consistent yield enhancement benefits as compared with conventional fertilizers across a range of soils, crops, and geographies.

Abstract Wheat ( Triticum aestivum L.) remains a major staple crop, which is vulnerable to abiotic and biotic stresses that can be compounded by climate change. This review assesses the projected effects of climate change on wheat production globally with an emphasis on the Canadian Prairies. The review aims to (i) discuss the projected impact of climate change on the Canadian prairie cropping calendar, (ii) assess the potential impacts of climate change on pest dynamics and abiotic stresses, and (iii) discuss beneficial management practices that can be employed to tackle climate change in wheat production systems. Climate change will potentially shift the current Canadian prairie calendar earlier in the year, potentially increasing wheat yields. The impact of climate change on pests is tied to the cropping calendar and the pest involved. Abiotic stresses, except carbon dioxide, will be aggravated. Beneficial management practices, that is, biostimulants, ultra‐early seeding, seeding winter wheat, and cultivar mixtures, are potential strategies to stabilize wheat yield and reduce the yield gap under a changing climate. Biostimulants, although effective, have not been extensively tested for their impact on abiotic stresses in the Prairies. Studies on ultra‐early warrant further research to address their effectiveness in Northern prairie regions and the challenges encountered by producers. Although growing winter wheat is an option to escape wetter spring conditions, issues with fall establishment and winter survival must be addressed. Despite the extensive global research on varietal mixtures, a knowledge gap exists regarding their benefits in the Canadian prairie context.

Abstract This study explores how scientists can support on‐farm experiments using analytical methods that align with farmers’ endogenous learning processes to inform their management decision. Four maize ( Zea mays L.) farmers across 10 site‐years in New York participated in this study to evaluate the effectiveness of a nitrogen‐fixing inoculant (NFI) applied with a reduced side‐dress nitrogen rate. Farmers designed and implemented their own experiments using a range of layouts, including side‐by‐side comparisons and strip trials. Two analytical approaches were compared: a quantitative yield analysis using spatial regression, and a causal pathway analysis based on mechanistic steps informed by field sampling (e.g., quantitative polymerase chain reaction detection of NFI organisms, nitrogen nutrition index, and yield). While yield data suggested positive or neutral treatment effects at all sites when simply comparing yield average, the spatial regression analysis and causal pathway analysis identified positive outcomes in only seven or four of 10 site‐years, respectively, reflecting a more conservative interpretation of efficacy. Both methods provided consistent conclusions at four out of 10 site‐years, demonstrating the contribution of metrics other than yield in the interpretation process. Findings suggest that simple causal diagrams can structure data collection and interpretation in ways aligned with farmers' goals. Supporting farmer experiments with digital agronomy, mechanistic reasoning, and site‐specific data enhances learning outcomes and scientific rigor without requiring formal replication. This work contributes to the development of collaborative, scalable methodologies that integrate farmer knowledge and scientific analysis in on‐farm experimentation.

Abstract Farmers often conduct unreplicated on‐farm experiments (OFE) to evaluate management practices such as the application of plant growth regulators (PGR) in winter wheat ( Triticum aestivum L.). Traditional methods of comparing strip average yields, such as using weigh wagons or yield monitors, lack error estimates and are causally confounded by field variability. Prescription (Rx) maps with randomization and replication may reduce causal confounding but are not always feasible. We propose a methodology to improve causal inference from unreplicated strip trials using propensity score matching (PSM). PGR strip trials were implemented using growers’ fields and equipment at two sites. Yield data, topographic covariates, and soil properties were collected. Propensity scores were calculated and used to create weights for covariate balancing. Next, treatment effect estimates and 95% confidence intervals were calculated for each site using G‐computation. Various benchmark models were included to compare the results of commonly implemented spatial models to the results from PSM. Spatial benchmark models showed evidence of spatial confounding, a purely statistical artifact rather than a causal effect. This artifact may alter treatment estimates and test statistics in strip trials where experimental units are not randomized throughout the field. PSM has potential to address the lack of replication and randomization in simple two‐treatment strip trials. PSM can potentially increase accessibility to rigorous OFE and improve decision‐making in agricultural practices, particularly in contexts where traditional experimental designs present barriers to participation.

Abstract Milk thistle ( Silybum marianum L.) is highly valued for its medicinal properties. It is renowned for its capacity to flourish in dry environments, making it an attractive option for farming in areas with scarce water resources. This study aimed to assess how drought stress, foliar potassium sulfate application, and their interaction affect different milk thistle genotypes. Ten different genotypes (nine Iranian and one Hungarian) were assessed under three levels of soil water availability including control, moderate, and severe water stress, with depletion rates of 40%, 60%, and 80% of available water, respectively. Also, two foliar treatments were applied (non‐spray and K 2 SO 4 spray). Foliar K 2 SO 4 application was applied twice, 7 days apart, during the flower bud development stage, using a 2% concentration in both 2020 and 2021. Drought stress adversely affected physiological parameters such as relative leaf water content and photosynthetic efficiency but enhanced antioxidant enzyme activities and osmotic adjustment mechanisms. K 2 SO 4 foliar application exhibited dual effects, increasing yield while reducing key bioactive compounds including phenol and flavonoids content of seeds. Genotype‐specific responses highlighted varying degrees of tolerance to drought stress and potassium application. Sari exhibited sensitivity to drought, while Isfahan and Hungary genotypes showed tolerance to moderate water stress with potassium foliar spray. Principal component analysis revealed the relationship of traits and genotypes by traits in each moisture condition. The study underscores the complexity of drought response mechanisms and the need for tailored management strategies and genotype selection to ensure resilience and optimize yield in milk thistle cultivation.

Abstract Nearly 1 billion ha of soils affected by salinization have been identified worldwide (8.7% of the planet's soils). These soils are mainly found in naturally arid or semi‐arid environments. The map also shows that 20%–50% of irrigated soils across all continents are too saline. Thus, soil salinity is one of the most critical threats to food security. It adversely affects the growth and productivity of agricultural crops. Tomato is the most important horticultural plant and an essential annual crop for human food worldwide. The effects of salinity on tomato ( Solanum lycopersicum L.) plants have been studied in recent years by several researchers. Attempts to improve tomato salinity tolerance through conventional breeding programs have had limited success due to the complexity of the trait. Thus, various cultural techniques, in addition to varietal selection, are applied to mitigate the harmful effects of salinity, such as seed pretreatments through priming methods, chemical fertilizers, and organic amendments like the use of beneficial soil microorganisms, including plant growth‐promoting rhizobacteria and arbuscular mycorrhizal fungi. This review paper provided valuable information on the behavior of tomato cultivars under saline conditions. The review also provides a synthetic overview of current and relevant scientific advances allowing the improvement of salinity tolerance of tomato plants. However, natural seed or soil treatments to combat salinization have not been widely developed. Nevertheless, the strategies developed in this review, combined with recent advances in emerging biotechnological solutions, could allow mitigating the effects of salinity on tomato plants.

Abstract Soil inundation increases anaerobiosis, slows organic matter decomposition, and affects greenhouse gas production from soils. The objective of this study was to evaluate the effects of natural short‐duration recurring inundation on CO 2 , CH 4 , and N 2 O emissions, as well as on labile soil permanganate oxidizable carbon and autoclaved‐citrate extractable (ACE) protein contents. We assessed two locations in Ohio separately: (1) in the Northwestern location, hayfields prone to high inundation (N‐HIH), low inundation (N‐LIH), and non‐inundated (N‐NIH), and (2) in the Southern location, pasture fields prone to inundation (S‐IP) or non‐inundated (S‐NIP) and non‐inundated hayfield (S‐NIH). Inundation was not controlled or simulated; rather, we evaluated it as a long‐term natural effect. We collected greenhouse gas (GHG) samples in spring, early and late summer, and fall of 2021 and 2022. At Northwestern location, N‐LIH and N‐HIH emitted less CO 2 , likely because of lower organic matter oxidation under more intense inundation. This pattern was less evident in the Southern location, where S‐NIP and S‐IP generally showed similar CO 2 emissions. Both locations acted as CH 4 sinks, and emissions remained largely unaffected by inundation at either location, suggesting that inundation duration and/or intensity were insufficient to maintain anaerobic conditions. Inundation, however, clearly increased N 2 O emissions in both locations, especially during the drying period in early and late summer, after the wetter spring seasons, characterizing a progressive response to inundation. We frequently observed the highest N 2 O emissions alongside elevated soil ACE protein levels. Natural recurring short‐term inundation increased GHG emissions from hayfields and pastures, mainly by increasing N 2 O emissions during post‐inundation periods.

Abstract Nitrogen (N) fertilizer recommendations in crops are affected by various factors including environmental and management practices. Effective N management should sustain maize ( Zea mays L.) yield while minimizing nitrate (NO 3 ‐N) leaching. This systematic review synthesized 132 peer‐reviewed studies to quantify how recommended N rates (RNRs) vary across environmental and management factors, and to evaluate associations between RNRs, yield, and NO 3 ‐N leaching. RNRs were grouped into quartiles derived from the empirical distribution of the study‐level RNR values in the review dataset. RNRs were generally higher (>200 kg ha −1 ) in subtropical and dry climates, in coarse‐textured soils, and under irrigation. Yield responses to RNRs tended to be stronger in temperate climates, in coarse‐textured soils, with conventional N sources, under split applications, and with irrigation. Studies conducted in semi‐humid climates and in fine‐textured soils showed weaker and inconsistent associations. NO 3 ‐N leaching increased with RNRs under irrigation‐based studies. Apparent increase in NO 3 ‐N leaching in medium‐textured soils likely results from residual N accumulation and post‐harvest flushing where rainfall is high. These findings should be interpreted cautiously due to uneven study coverage and heterogeneous methods. Several key gaps remain in the evidence base. First, few studies quantify environment‐by‐management interactions. Second, NO 3 ‐N leaching is rarely measured, and irrigation amount scheduling is often unreported. Third, paired irrigated‐rainfed comparisons are uncommon. Finally, criteria for deriving RNR are inconsistent, and geographic coverage is limited. Research priorities include integrated factorial designs across climates and textures, water‐accounted paired designs, concurrent residual‐N profiling, long‐term trials, transparent RNR definitions, and curated open datasets to enable synthesis.

Abstract Nitrogen (N) fertilizers have played a critical role in increasing crop yields, yet only about 48% of applied N is recovered by crops, with the remainder lost through leaching, volatilization, denitrification, immobilization, or runoff, posing environmental and agronomic concerns. This study quantified partial N budgets across three yield‐based zones (yield zone 1 [YZ1]: stable high yield; yield zone 2 [YZ2]: stable low yield; yield zone 3 [YZ3]: unstable yield) in a 190‐ha commercial row crop system in northern Alabama over four cropping seasons (2021–2024). Nitrogen inputs included mineral‐N present at planting, fertilizer, manure, irrigation, biological fixation, atmospheric deposition, and crop residues; outputs included crop N uptake, residual mineral N at harvest, and runoff losses. Unaccounted‐for N was used as a proxy for potential losses via gaseous pathways, leaching, and immobilization. Among crops, maize ( Zea mays L.) received the highest N input (up to 421 ± 4 kg/ha), while wheat exhibited significantly higher unaccounted‐for N (113 ± 31 kg/ha). Across all years and crops (excluding soybeans), YZ2 consistently reported significantly higher unaccounted‐for N (97 ± 52 kg/ha), highlighting inefficiency in current management practice. In contrast, soybean ( Glycine max L.), as a legume crop, showed negative N balances in YZ1 (–33 ± 18 kg/ha), indicating it was able to meet its N requirement through biological fixation and, in some cases, contributed additional N to the soil. Runoff monitoring from two watersheds, falling under YZ1 and YZ3, revealed higher cumulative N losses from YZ3 (6 kg/ha) than YZ1 (1 kg/ha), particularly during the wheat and fallow periods. These findings emphasize the importance of yield‐based, zone‐specific N management strategies to improve N use efficiency and mitigate environmental losses across spatially variable production systems.