Abstract Vetch ( Vicia spp .) is a promising forage legume for Ethiopian livestock systems, but limited information exists on genotype performance across diverse environments. This study evaluated forage yield, quality, and agronomic traits of four vetch genotypes ( Vicia villosa DZF , Vicia sativa, Vicia dasycarpa , and Vicia atropurpurea ) across two locations (Endasilassie and Wefargf) in Western Tigray, Ethiopia, over three cropping seasons (2021–2023). A randomized complete block design with three replications was used. Genotype, location, and their interaction were analyzed using linear mixed models. Significant genotype effects were observed for days to 50% flowering, survival rate, branch number, dry matter yield, and seed yield. Location significantly influenced flowering, survival, branching, plant height, and seed yield. Genotype × location interactions were significant for flowering ( p = 0.0217) and dry matter yield ( p = 0.0357), indicating location‐specific performance within the tested environments. V. dasycarpa produced the highest dry matter yield (13.61 t ha − 1 ) at Endasilassie, while V. villosa DZF showed superior survival and stability at Wefargf. Nutritional quality traits (crude protein [CP], neutral detergent fiber, acid detergent fiber, acid detergent lignin, in vitro dry matter digestibility) showed significant genotype effects, with minimal environmental modulation across the tested environments. V. dasycarpa exhibited the highest CP (25.7%) and digestibility (73.6%), and the lowest fiber fractions. Variance component analysis revealed trait‐specific environmental sensitivity; however, these estimates should be interpreted cautiously due to the limited number of genotypes and locations. Based on these findings, V. dasycarpa and V. villosa DZF are recommended for forage biomass production at Endasilassie and Wefargf, respectively, pending validation through additional multilocation trials.
Abstract Application of nitrogen (N) fertilizer in rice ( Oryza sativa L.) has been increasing and sustaining yield; however, its inadvertent use has resulted in N‐induced pollution, as rice has the lowest nitrogen use efficiency (NUE) among cereals. To mitigate these effects, there is a need to assess the performance of rice germplasm for NUE. This study evaluated 20 rice landraces for 12 N‐responsive traits using a two‐factor factorial completely randomized design under N‐optimum (8 mM N) and N‐stress (0.08 mM N) in greenhouse conditions for 28 days. Significant phenotypic variability was observed across all N‐responsive traits. N‐stress increased root length (35.93%) and root dry weight (30.43%) while significantly reducing shoot dry weight (27.88%), total chlorophyll (35.73%), and carotenoid content (42.14%). principal component analysis and genotype plus genotype‐by‐environment biplots showed that root traits were primary indicators of performance under N‐stress conditions. Landraces such as Jungey Kanchi and Kamal exhibited promising performance under N‐optimum conditions, whereas Biramphul showed excellent results under N‐stress conditions. Jungey Kanchi and Mansara were identified as the most superior and adaptable landraces based on their high mean performance and high stress susceptibility index scores. Conversely, Darmali, Pahele, and Noulo Dalley were classified as poor performers. This study highlights the potential of specific Nepalese landraces as promising candidates for further studies aimed at enhancing NUE. These findings also provide a foundational benchmark for developing N‐stress‐tolerant rice cultivars. However, more comprehensive insights can be gained by evaluating their tolerance during subsequent stages and identifying genes associated with NUE using omics approaches.
Abstract Soil organic carbon (SOC) fractionation methods are widely used to assess different carbon (C) pools, but their reproducibility, particularly with depth, remains unclear. This study evaluated the within‐site variability of chemical and physical fractionation methods for SOC at 0‐ to 30‐cm and 30‐ to 60‐cm depths across four apple ( Malus domestica ) orchards in northern Italy. All measured fractions: total organic carbon (TOC), dissolved organic carbon (DOC), hot water extractable carbon, permanganate oxidizable carbon (POXC), fulvic acids, humic acids, particulate organic matter carbon (POMC), particulate organic carbon (POC), and mineral‐associated organic carbon (MAOC) decreased significantly with depth; subsoils contained less than half the C of topsoils. Reproducibility declined in subsoil, with higher coefficient of variation, especially for POXC and MAOC (∼80%). Heterogeneity in subsoils was attributed to lower organic matter concentrations, greater C heterogeneity, texture differences, and more complex soil structure. POC and DOC exhibited lower variability in subsoil than topsoil, suggesting a reduced sensitivity to short‐term changes and therefore more stable indicators of subsoil C dynamics. The combined measurement of POC and MAOC, alongside DOC, reliably represented TOC at both depths, with POC + MAOC values closely aligning with measured TOC. Future studies should work toward improving fractionation protocols and normalization techniques to enhance both accuracy and comparability, particularly in the complex conditions of subsoil. This research adds valuable insight into C dynamics at depth and offers practical recommendations for choosing appropriate fractionation methods. It also underscores the need for careful consideration when comparing C fractions reported in different studies.
Abstract Rice ( Oryza sativa L.) is a critical staple crop, necessitating continuous genetic improvement to enhance yield and quality traits to meet global food demands. This study aims to identify high‐yielding genotypes with desirable quality traits and elucidate the relationships among traits to inform breeding strategies. Twenty‐seven rice genotypes were evaluated for genetic variability, heritability, genetic advance, and trait associations. Nine agronomic traits were measured: grain yield, days to maturity, plant height, productive tiller number, 1000‐grain weight, grain length, grain width, grain shape, and awn length during the 2021–2023 cropping seasons. Analysis of variance revealed highly significant differences ( p < 0.01) among genotypes for all traits, demonstrating pronounced phenotypic variations that suggest a diverse genetic background among the studied genotypes. Grain yield ranged from 4.38 t ha − 1 (Gerdeh) to 7.73 t ha − 1 (Shiroudi), with a mean of 6.052 t ha − 1 . Broad‐sense heritability ( H 2 ) was high (0.926–1.0) for all traits. Traits with both high heritability and high genetic advance as percentage of mean (GA% > 20%)—namely, grain shape, productive tiller number, grain yield, grain width, and grain length—are likely to respond effectively to direct phenotypic selection. Correlation analysis showed significant positive associations between grain yield and days to maturity ( r = 0.532, p < 0.01), 1000‐grain weight ( r = 0.266, p < 0.05), grain length ( r = 0.269, p < 0.05), and grain shape ( r = 0.269, p < 0.05), but a negative correlation with awn length ( r = −0.406, p < 0.01). Path analysis identified days to maturity (direct effect = 0.341, p < 0.001) and grain shape (0.241) as key yield contributors. Hierarchical clustering grouped genotypes into four clusters, with Cluster 4 (including Shiroudi, Keshvari, and Neda) containing high‐yielding genotypes. These results provide clear guidance for designing efficient breeding programs through targeted selection of superior genotypes and trait‐based strategies. Shiroudi and Cluster 4 genotypes are promising candidates for breeding high‐yielding, quality rice varieties.
Abstract Leafspot disease causes up to 70% yield losses in peanut production areas across the globe. One way to curb this menace is to use leafspot resistant peanut ( Arachis hypogaea L.) varieties. In breeding for disease resistance, quantitative characterization of disease dynamics, including initial inoculum ( y 0 ) and apparent infection rate ( r ), is essential for improving disease assessment, resistance evaluation, and the development of future decision‐support systems in agriculture. This study evaluated the performance of commonly used nonlinear models for characterizing leafspot disease incidence (DI) and severity in peanut genotypes. Field‐based time‐series data on leafspot DI, early leafspot (ELS) severity, and late leafspot (LLS) severity were collected on 10 peanut genotypes over two growing seasons. Disease progress was analyzed using both linearized and nonlinear forms of the Gompertz, logistic, monomolecular, and exponential models. Model‐derived parameters revealed clear genotypic differences: resistant genotypes (Nkatiesari, Sarinut‐1) exhibited low y 0 and r , moderately resistant genotypes (L010A1, L027B, L076J) showed intermediate dynamics, and susceptible genotypes (L030, L046, L104B, Chinese, Sarinut‐2) displayed rapid epidemic amplification. The Gompertz and exponential models generally provided the best fit for DI and ELS severity, whereas LLS severity exhibited greater interannual variability, with logistic and monomolecular models performing best in different years. These findings provide a comparative modeling framework to support the quantitative evaluation of crop disease dynamics and highlight the value of nonlinear disease progress models for agricultural disease assessment and resistance evaluation.
Abstract Agricultural practices are constantly evolving due to changes in regulation, climate, and technology. Regulations in California resulted in phasing out rice ( Oryza sativa L.) straw burning in the 1990s, leading to a range of alternative practices to manage the straw, which impact agronomic practices, air quality, ecosystem services, and wildlife habitat. It is important to understand how these practices change over time. To address this, we conducted post‐harvest surveys during the winters of 2016/2017 and 2017/2018. We visually observed 1146 fields representing about 8% of the total rice area to determine the straw management practices implemented (unmanaged, burn, bale, chop, or incorporate) and winter irrigation (flooded or non‐flooded). We also compared these results to historical data. Over 2 study years, an average of 52% of fields were flooded. In all fields, straw incorporation was the primary practice used. Comparing these findings to previously published data, the largest changes were documented in two practices between the 1980s and 2007. Burning dropped from as high as 40% (1980s) to <2% (2007 onward), in contrast, flooding increased from <16% to over 40%, respectively. From 2007 to 2018, there were no major changes to post‐harvest field management and those that were observed could be attributed to the amount of fall rainfall. Despite little change to the relative proportion of practices used, the area planted to rice changed significantly (>25%); thus, the area under each practice changed considerably. This has important implications for winter water allocations, greenhouse gas inventories, and wildlife habitats.
Abstract Soybean ( Glycine max [L.] Merr.) harvesting in Ghana is predominantly manual, and labor shortages frequently delay harvest beyond physiological maturity, exacerbating shattering losses. Mechanization could mitigate these losses, but effective combine harvesting requires cultivars with elevated first pod height (FPH) to minimize header losses. Twenty soybean genotypes were screened across three environments (2022–2023), from which three early‐maturing candidate varieties (ENT1, ENT3, and ENT4 where ENT is Experimental Entry [Candidate Variety Code]) were advanced into a six‐environment validation trial (2024). Genotype performance was evaluated using analysis of variance and genotype + genotype × environment (GGE) biplots, while participatory varietal selection (PVS), proximate analysis, sensory evaluation, and benefit‐cost analysis were employed to assess farmer preference, end‐use quality, and economic viability for adoption. Genotypic differences were highly significant ( p ≤ 0.001) for FPH and grain yield (GY) in both screening and validation trials. Genotype × environment interactions were nonsignificant for all traits in the validation trials, confirming success in selection. The candidate varieties exhibited FPH > 15 cm and GY of ∼2686–2778 kg ha −1 , representing a 60%–66% yield advantage over the check (FPH = 4.5 cm; GY = ∼1678 kg ha −1 ). GGE biplot analysis supported ENT3 and ENT4 as high‐performing and stable, with ENT4 ranking highest under PVS involving 540 farmers. Candidate varieties matched the checks for protein and oil concentrations and maintained acceptability for soy milk and tofu. Benefit‐cost ratios were higher for the candidate varieties (1.60–1.64) than the check (0.98), confirming economic viability. These results support ENT1, ENT3, and ENT4 as promising candidate varieties possessing mechanized harvest‐enabling traits for future on‐farm combine‐harvest validation in Ghana.
Abstract Climate change is exerting profound and multidimensional pressures on global wheat ( Triticum aestivum L.) production. Rising temperatures, higher vapor pressure deficit, and more frequent heatwaves reduce yields through strong, phenology‐dependent effects, with flowering and grain filling identified as the most vulnerable stages. Compound heat–drought events disproportionately depress grain number and weight, while erratic precipitation marked by prolonged dry spells, intense rainfall, and waterlogging further destabilizes yield and degrades soil fertility. Meta‐analytic evidence shows wheat yield reductions exceeding 50% under drought and ∼23% under waterlogging, with associated declines in grain quality. Elevated CO 2 enhances photosynthesis and biomass in optimal conditions but fails to compensate for warming or drought and often lowers grain protein and mineral concentrations. Soil degradation, salinity, and nutrient imbalance are intensifying, while warming accelerates pest survival, reproduction, and geographic expansion, increasing biotic stress risks. Despite these challenges, multiple adaptation pathways demonstrate strong effectiveness. Drought‐tolerant cultivars, optimized sowing dates, deficit irrigation, mulching, conservation agriculture, and soil restorative practices significantly improve resilience. Precision agriculture, unmanned aerial vehicle remote sensing, Internet of Things‐enabled monitoring, and artificial intelligence (AI)‐driven decision‐support tools enhance early stress detection and management precision. Economic evidence consistently shows high returns from climate‐smart interventions. Strengthening policy coherence, climate‐informed services, and agricultural financing is essential to scale adaptation and secure wheat production under a warming climate.
Abstract Hailstorm losses are associated with plant defoliation, stand losses, and reduced crop canopy capacity to compete with weeds. Additionally, hail wounds in plants might favor disease development, potentially further reducing corn yields. Corn yield losses due to hailstorms early in the growing season are considered minor due to an expected plant recovery potential. However, favorable conditions for plant recovery and disease establishment can vary widely. This study evaluated simulated hailstorms at the V3–V4 stage and Goss's wilt inoculation ( Corynebacterium nebraskense ) across four planting dates (PDs): May 11 (PD1), May 28 (PD2), June 11 (PD3), and June 23 (PD4). Two corn hybrids (one tolerant and one susceptible to Goss's wilt) were sown on each PD. For each PD and hybrid, treatments included a control (unhailed check), simulated hail, and simulated hail + Goss's wilt inoculation. Increasing damage scores (0–4) were assigned to plants according to injury levels 7 and 14 days after hail simulation. Overall, yields were reduced as the plant damage score increased ( R 2 = 0.72), and yields increased as a function of increasing plant stands ( R 2 = 0.68). Hail and hail + Goss's wilt decreased average corn yields by 20% and 25%. With Goss's wilt inoculation, corn yields were lower than hail alone in PD2 and PD3. If the main stems were not damaged, yields did not differ from control plots. Surviving plants that had damaged stems had lower yields. This study highlights the potential unaccounted yield loss of surviving plants when using standard surviving plant stand count assessments in corn.
Abstract Kettle‐holes are small but biogeochemically active landscape elements that integrate terrestrial inputs and influence carbon and nitrogen cycling. However, the stability and sources of organic matter (OM) in kettle‐hole sediments remain poorly understood. We combined thermogravimetric analysis with stable isotope measurements (δ 1 3 C and δ 1 5 N) to assess the influence of arable, forest, and grassland land uses on the composition and stability of OM in kettle‐hole sediments of northeastern Germany. Thermal fraction analysis showed broadly similar OM composition among all land‐use types, although some differences were observed. Forest sediments showed highest proportion of Fraction 2 (45.3%), while grassland sediments contained the lowest (38.7%). Grassland sediments also showed a greater proportion of thermally stable fractions (Fractions 4–5: 11:0%) compared with arable (6.9%) and forest sediments (6.0%). δ 1 5 N values ranged from −0.3 ± 1.7‰ (Forest) to +3.7 ± 0.3‰ (arable), suggesting contrasting nitrogen sources and/or processing, while δ 1 3 C values (−28.7‰ to −28.3‰) showed minimal variations across land uses. Statistical analysis revealed a marginal land‐use effect on OM fractions ( p = 0.048), with no significant pairwise differences among land‐use types. The results indicate that differences in OM stability across land uses are subtle and should be interpreted cautiously. The integration of thermal and isotopic approaches provides complementary insights into OM dynamics, although isotopic differentiation in this study was primarily driven by δ 1 5 N. Overall, this study highlights the importance of considering both OM stability and source indicators when evaluating sediment carbon dynamics in small landscape features.
Abstract Cover crops are being encouraged due to benefits to soil health and ecosystem services, but they could negatively affect subsequent forage production and system profitability in regions with limited water availability. The objectives of this study were to determine the effects of cover crop treatment and termination date on wheat ( Triticum aestivum L.) forage biomass, crude protein, and total digestible nutrients, and to determine the cover crop/wheat forage production system that was most profitable. Data collected were from a 4‐year (2017–2021) randomized complete block design agronomic study conducted in south‐central Oklahoma. The experiment included two summer fallow treatments as controls and seven summer cover crop treatments (each divided into either early or late termination) for a total of 16 production systems. A mixed‐effects regression model indicated that the choice of summer cover crop had no effect ( p = 0.23) on wheat forage biomass, but early termination significantly increased wheat forage biomass compared to late termination ( p = 0.0001). Effects of cover crop treatment and termination date on crude protein and total digestible nutrients were not significant. The no‐till summer fallow production system had the highest relative net return, equal to $67 ha −1 . Cover crop systems, compared to the no‐till fallow control, were not profitable because they were costly to establish and provided little to no yield boost. Early cover crop termination increased forage yield, but not enough to make cover crops profitable relative to no‐till fallow. Results suggest cover crops are unlikely to be widely adopted in water‐limited wheat systems in the Southern Great Plains.
Abstract Limited winter rainfall and rising irrigation costs threaten sustainable Naga chili ( Capsicum chinense Jacq .) production in Bangladesh. However, the combined effects of crop‐specific irrigation and soil‐test‐based fertilization on Naga chili productivity and resource‐use efficiency remain poorly understood. Therefore, a field experiment was conducted to evaluate the influence of irrigation and fertilizer management on growth, yield, irrigation water use efficiency (IWUE), and nutrient use efficiency of Naga chili. The experiment was conducted in a randomized complete block design with two irrigation levels: conventional irrigation (CI) and climate‐smart irrigation (CSI), and three fertilizer management practices: farmers’ practice (FP), soil‐test‐based recommended fertilizer dose (RFD), and soil‐test‐based recommended fertilizer dose plus organic matter (RFD + OM). Growth parameters, fruit characteristics, and yield were not significantly affected by irrigation or fertilizer management. However, individual fruit weight was significantly affected by irrigation ( p < 0.033), fertilizer management ( p < 0.021), and their interaction ( p < 0.005). CI produced higher individual fruit weight (6.5 ± 0.19 g) than CSI (6.1 ± 0.19 g), while FP and RFD + OM resulted in higher fruit weight than RFD alone. A significant irrigation × fertilizer interaction indicated that higher fruit weight under FP occurred only under CI. In contrast, CSI combined with soil‐test‐based fertilizer management maintained comparable fruit weight under reduced input conditions. CSI significantly increased IWUE ( p < 0.001), while soil‐test‐based fertilizer management significantly improved nutrient (nitrogen) use efficiency ( p < 0.001). The findings demonstrate that crop‐specific irrigation combined with soil‐test‐based fertilizer application can maintain Naga chili growth and yield while improving water and nutrient use efficiencies.
Abstract Land‐use changes impact soil physical quality and carbon stocks. Most studies evaluating the conversion of native Brazilian Cerrado to agriculture focus on surface soil layers (up to 40 cm), with fewer examining deeper layers (0–100 cm). This study assessed the impacts of different land‐use systems on soil physical attributes and soil organic carbon stock (SOCS) in a Latossolo Vermelho (Oxisol) following the conversion of native Cerrado vegetation. The evaluated areas consisted of native Cerrado, a chronosequence of no‐tillage systems (NTS) managed for 2, 11, and 20 years, a silvopastoral system (SS) managed for 37 years, and a degraded pasture established for nearly 50 years. Soil samples were collected from the depths of 0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm to determine physical attributes related to soil porosity and aggregation and to calculate SOCS. The SS exhibited the greatest potential to provide ecosystem services, due to improved soil porosity, aggregation, and carbon storage (146.6 Mg ha −1 ). The NTS also presented a higher SOCS (ranging from 111.5 to 112.9 Mg ha −1 ) than the Cerrado (102.8 Mg ha −1 ), although negative changes in physical attributes were detected in the long‐term. Across all evaluated land‐use and management systems, approximately half (44%–53%) of the carbon in the 1‐m‐deep soil profile was stored below 40 cm, highlighting the significant contribution of subsurface soil layers to organic carbon stocks.
Abaca (Musa textilis Nee) is a fiber crop, closely related to banana (Musa sp.). However, it requires 15-18 months from transplanting to first harvest, leaving the soil between plants vulnerable to erosion or weed infestation. Integrating cover crops into abaca plantations may help mitigate these issues. This study aimed to examine the influence of diverse cover crop species on abaca production during its early and late growth phases. Two experiments were conducted to assess the impacts of cover crops on abaca. First, the impact of forage peanut (Arachis pintoi) and koronivia grass (Brachiaria humidicola) on mature abaca plants was investigated. Second, the influence of peanut (Arachis hypogaea), mung bean (Vigna radiata), and upland rice (Oryza sativa) on young abaca was evaluated. Each experiment included a no-cover crop treatment. In the mature abaca field, forage peanut produced an average biomass of 1093 kg ha(-1) with a carbon:nitrogen (C:N) ratio of 14:1, whereas koronivia grass yielded 956 kg ha(-1) with a C:N ratio of 26:1. Despite these differences, microbial biomass (606 & micro;g C g(-1) soil) and soil N were similar among treatments. In the young abaca field, peanut, mung bean, and upland rice produced 1351, 1036, and 743 kg ha (-1), respectively. After 71 days, soil inorganic N (128 mg kg(-1)) was numerically higher with cover crops than without (108 mg kg(-1)) with no difference observed on microbial biomass. Overall, cover crops did not hinder abaca growth, indicating their potential to enhance sustainability and soil health in abaca system.
Abstract Alfalfa ( Medicago sativa ) is a widely cultivated forage legume valued for its high forage mass and nutritive value but is often associated with pasture bloat in ruminants. Interseeding alfalfa with sainfoin ( Onobrychis viciifolia ), a tannin‐rich legume known for its anti‐bloating properties and environmental benefits, has emerged as a potential solution. A 2021–2023 field trial evaluated the impact of interseeding alfalfa with sainfoin on forage mass, nutritive value, and condensed tannin (CT) concentration near Cedar City, UT. Two treatments, alfalfa monoculture (Mono) and alfalfa–sainfoin mixture (Mixed), were established in 2021. In the establishment year, the mixed system showed a roughly 10% forage mass advantage compared to Mono, though no consistent difference was observed in subsequent years. Forage nutritive value parameters were primarily influenced by cutting time and seasonal variation rather than treatment. Despite limited treatment differences, crude protein, relative feed value, relative forage quality, and total digestible nutrients values in both systems consistently met USDA criteria for “supreme” quality hay. CT concentrations varied significantly by treatment, year, and cutting. Notably, in 2022, the mixed system showed substantially higher CT concentrations during early cuttings compared to the monoculture alfalfa (0.823% vs. 0.20% in the first cutting and 0.47% vs. 0.25% in the second cutting), indicating that sainfoin can meaningfully enhance forage CT concentration when well‐established, but not consistently. These findings suggest that interseeding sainfoin may offer early‐season benefits in both forage mass and bloat‐mitigating potential, though year‐to‐year variability and cutting stage may influence overall forage value.
Abstract Soybean ( Glycine max ) seed yield and quality are strongly affected by drought, particularly during reproductive stages. We evaluated 22 genotypes under irrigated and rainfed conditions across three Missouri environments (2023–2024) for seed yield, 100 seed weight, protein, oil, and five fatty acids. Mixed models were used to partition genotype, environment, and genotype × environment effects and to obtain best linear unbiased predictions (BLUPs) for each trait. Seed yield showed strong environmental sensitivity, whereas protein, oil, and most fatty acids exhibited moderate to high broad‐sense heritability ( H 2 = 0.65–0.95), indicating good prospects for genetic gain. Performance and stability were jointly assessed using the weighted average of absolute scores from BLUPs (WAASB) and the multi‐trait stability index (MTSI). WAASB biplots highlighted genotypes G9, G13, and G17 as combining below‐average WAASB with favorable mean performance for seed yield and key quality traits. MTSI rankings confirmed these three lines as the most desirable multi‐trait ideotypes. Selection based on WAASB and MTSI increased mean yield from 2603 to 2775 kg ha −1 (+5.17%) and oil from 17.7% to 17.9% (+1.05%), while slightly reducing protein (−0.49%) and oleic acid (−1.60%) and substantially decreasing linolenic acid (−5.00%), improving oil stability. These results demonstrate that BLUP‐based stability metrics integrated with MTSI provide an effective decision‐support framework for identifying drought‐resilient, high‐value soybean cultivars for variable water regimes.
Abstract Groundwater contamination has prompted the Environmental Protection Agency to consider restricting atrazine use, highlighting the need for alternative preemergence herbicides in grain sorghum ( Sorghum Moench). Research was conducted in 2023 and 2024 to evaluate grain sorghum tolerance and weed control from preemergence applications of amicarbazone (490, 735, and 980 g ai ha −1 ) and metribuzin (280, 420, and 560 g ai ha −1 ), applied alone and in combination with commonly used herbicides. Metribuzin applied alone caused ≤3% injury across evaluation timings, whereas amicarbazone at 980 g ha −1 caused 17% injury 5 weeks after treatment (WAT). Combining amicarbazone (980 g ai ha −1 ) with metribuzin (560 g ha −1 ) resulted in 38% injury, delayed panicle emergence by 3 days, and reduced grain yield by 43% points compared with the nontreated control. Weed control trials evaluated preemergence combinations of amicarbazone, metribuzin, atrazine, S ‐metolachlor, and mesotrione. On a silt loam soil, amicarbazone provided comparable Palmer amaranth control to atrazine 4 WAT in 2023 and greater weed control in 2024. Greater than 96% control of broadleaf signalgrass, common lambsquarters, spurred anoda, and ivyleaf morningglory 4 WAT was achieved with amicarbazone alone or with S ‐metolachlor + mesotrione preemergence. Amicarbazone + metribuzin resulted in similar weed control, but this treatment induced up to 40% injury to grain sorghum. Although effective weed control was achieved with amicarbazone + metribuzin treatments, injury and grain yield reductions warrant additional research to find a less injurious preemergence alternative to atrazine or a herbicide safener for amicarbazone + metribuzin in grain sorghum.
In recent years, the escalating application of nitrogen fertilizers in global vegetable production has positioned vegetable fields as significant sources of nitrous oxide (N 2 O) emissions, eliciting widespread environmental concern. However, the interrelationships among fertilizer reduction gradients, soil physicochemical properties, microbial biomass nitrogen (MBN), enzyme activities, N 2 O emissions, and yield in highland summer cauliflower ( Brassica oleracea var . botrytis L.) systems remain inadequately elucidated. This study, conducted in Yuzhong County, Lanzhou City, Gansu Province, employed the “Green Stalk 100‐day” cauliflower variety under three fertilization regimes: CK (conventional fertilization), F1 (20% fertilizer reduction), and F2 (40% fertilizer reduction). The impacts of these treatments on soil properties, MBN, enzyme activities, N 2 O emissions, and yield were systematically evaluated. Results demonstrated that compared with conventional fertilization, both F1 and F2 significantly reduced soil organic carbon, nitrate nitrogen (NO 3 − ), ammonium nitrogen (NH 4 + ), total phosphorus, and MBN. Cumulative N 2 O fluxes under F1 and F2 decreased by 30.01% and 63.35%, respectively, relative to CK, with a pronounced declining trend as the growing season progressed. Both greenhouse gas balance (GHG) and greenhouse gas intensity (GHGI) were markedly reduced under reduced fertilization regimes. Additionally, under the F2 treatment, the biomass and yield of cauliflower exhibited significant reductions of 17.41% and 25%, respectively, relative to the control (CK). In contrast, F1 achieved substantial mitigation of N 2 O flux, GHG, and GHGI without compromising yield stability. In conclusion, the F1 treatment represents the optimal strategy for balancing economic and environmental benefits in highland summer cauliflower production systems in the Yuzhong region of Gansu Province.
Soil salinity and sodicity severely limit agricultural productivity in the Awash Basin of Ethiopia, demanding innovative reclamation strategies. This study evaluated the efficiency of phosphogypsum (PG) amendment at varying loadings under intermittent leaching using pore volume for saline-sodic clay loam soils at Kessem Sugar Estate, Ethiopia. Soil columns were treated with five PG loadings (equivalent to 50%, 75%, 100%, 150%, and 200% of gypsum requirement [GR]), locally mined gypsum (100% GR), and a control, followed by six leaching rounds using nonsaline, non-sodic water (sodium adsorption ratio = 1.15), with a total leaching depth of 33 cm. PG application at 100% GR loading and above had removed over 85% of salts, significantly reducing pH, electrical conductivity, and exchangeable sodium percentage to target levels. It also enhanced bulk density, total porosity, aggregate stability, and saturated hydraulic conductivity. Notably, desalinization and desodification trends were best described by an exponential model, providing a predictive framework for estimating leaching water requirements. These findings highlight PG as a superior amendment for reclaiming saline-sodic soils and introduce a scientifically grounded approach for optimizing reclamation practices. Field-scale validation focusing on nutrient dynamics, rate optimization, and economic feasibility is recommended to support sustainable saline-sodic soil management in Kessem Sugar estate and similar regions.
Abstract Use of cover cropping systems to improve soil health is still limited in Louisiana. This study aimed to examine the interaction between cover crops and nitrogen (N) fertilizer rates on crop yield, soil chemical, and biological properties. Winter cover crop treatments, including legumes, a grass and brassica, and a fallow control, were combined with N fertilizer application at four rates (0, 90, 179, and 269 kg N ha−1) in no‐till continuous corn (Zea mays L.) production. Soil samples were collected at 0–8 cm at cover crop termination in February (Spring) and before cover crop planting in October (Fall) between 2017 and 2018. Soil nutrients, organic matter, inorganic N, microbial community composition, and soil enzymes were analyzed. Legumes increased corn grain yield overall and maximized yield at 90 kg N ha−1 compared to grass and brassica treatments, which maximized corn grain yield at 179 kg N ha−1. Regardless of cover crop type, N fertilizer applications increased soil organic matter by 8% compared to no N applications. Concentrations of soil phosphorus (P) in the legume treatment were 19% higher than the grass and brassica treatment, while grass and brassica had a greater soil potassium (K) concentration than legume. The grass and brassica also increased soil N‐acetyl‐β‐d‐glucosaminidase activity. Nitrogen applications on corn increased soil microbial biomass and β‐glucosidase activity. Arbuscular mycorrhizal fungi were most abundant in the grass and brassica treatment when no N was applied. Overall, the incorporation of winter legumes could reduce N fertilizer input while sustaining corn production and benefit soil health.
