Agronomy Journal最新文献

The use of feed supplements can enhance land yield in crop-livestock integrated systems (CLIS). Thus, a study was conducted in Montes Claros de Goiás, Brazil, between 2020 and 2023. The system comprised soybean [Glycine max (L.) Merr.] cultivation during spring/summer (generally, sowing in November and harvesting in March), followed by Zuri guinea grass (Megathyrsus maximus ‘BRS Zuri’) cultivation grazed by beef cattle (heifers) during autumn/winter (generally, grazing from May to August). Three supplementation strategies were evaluated during this period: mineral supplementation with an expected intake of 0.03% of live weight (LW), protein-energy supplementation (0.5% of LW), and high-intake supplementation (1.5% of LW). Each supplementation strategy was applied to three paddocks (1.54 ha each), totaling nine paddocks (13.86 ha). Across the three management practices adopted, no differences were found; thus, the average soybean grain yield was 4.01 Mg ha⁻¹. Regarding the livestock phase of the evaluated system, the supplementation level of 1.5% of LW resulted in the highest values for stocking rate (3.64 AU ha⁻¹) and hot carcass weight (194 kg). Furthermore, for all crop seasons, this supplementation level promoted increases in carcass production per unit area, with average values of 1084, 872, and 839 kg ha⁻¹ measured in 2020, 2022, and 2023, respectively. Based on this, it is possible to infer that the higher supplementation level did not affect subsequent crop yields and promoted increases in meat production per unit area, enhancing human-eligible food production per unit of land.

Winter camelina (Camelina sativa L.) can be grown as an intermediate oilseed crop following spring wheat (Triticum aestivum L.) with soybean (Glycine max L.) relay planted the following spring into the camelina, producing three crops in 2 years. Winter camelina provides early spring ground cover that reduces soil erosion and improves water quality; however, camelina fall biomass production is limited. Here, we investigated whether interseeding tillage radish (Raphanus sativus L.) in the fall between rows of winter camelina improved fall soil cover, spring soil moisture, nitrogen cycling, and crop productivity of the winter camelina-soybean relay crop system. Soybean was planted into the winter-terminated tillage radish rows prior to camelina flowering in the spring. Data on NDVI, soil moisture, crop biomass, soil N and P content, weed populations, crop seed yield, and oil content were measured. Intercropping tillage radish with winter camelina increased fall soil coverage and early spring water infiltration over winter camelina alone in 1 out of 2 years. Tillage radish did not affect camelina growth or productivity, but had a positive effect on soybean yield (2703 kg ha⁻¹), oil content (222 kg ha⁻¹), and oil yield (600 kg ha⁻¹) as well as the total oil yield of camelina plus soybean (996 kg ha⁻¹) relative to the camelina only treatment (2401, 216, 520, and 925 kg ha⁻¹, respectively). Fall intercropping of tillage radish into winter camelina may be used to improve environmental benefits and overall system productivity of the winter camelina-soybean relay crop system.

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.

Plant growth regulators can enhance row crop productivity and nutrient use efficiency. We conducted 2 year field experiments (2020–2021) in the North Central China Plain (NCP) to evaluate a foliar ethephon-chlormequat chloride (ECC) and nitrogen (N) fertilizer rates (0, 60, 120, and 240 kg N ha⁻¹) on sorghum (Sorghum Bicolor (L.) Moench) yield and nitrogen use efficiencies (NUEs). The control treatment (CK) received a foliar water spray. ECC increased sorghum yield by an average of 4.5%, 5.9%, and 4.7% under 60, 120, and 240 kg ha⁻¹, respectively, relative to CK across 2 experimental years. Moreover, ECC significantly (p < 0.05) increased sorghum root biomass, root to shoot ratio, leaf nitrate reductase activity, chlorophyll content, and nitrogen uptake, thereby improving both nitrogen uptake efficiency and agronomic efficiency. Sorghum yield increased significantly with nitrogen application up to 120 kg ha⁻¹, with no additional yield gain beyond this rate. Nitrogen uptake increased with higher nitrogen rates up to 240 kg ha⁻¹, whereas nitrogen agronomic efficiency declined when nitrogen fertilization exceeding 60 kg ha⁻¹ in both experimental years. Overall, foliar spraying ECC at five-leaf stage, combined with 120 kg N ha⁻¹, achieved high sorghum yield and improved NUE in the NCP.

Zimdahl, R. L. (2025). Survey of deans of agriculture. Agronomy Journal, 117, e70216. https://doi.org/10.1002/agj2.70216

The special section title, “Special Section: Ethical Issues in Production Agriculture,” was missing in the original published article.

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This study calibrated and validated the Crop Environment Resource Synthesis-wheat model within Decision Support System for Agrotechnology Transfer to assess climate change impacts and evaluate adaptation strategies under various emission scenarios in Central Oromia, Ethiopia. Field data from three consecutive growing seasons (2021/22–2023/24) were used to calibrate the model's genetic coefficients, while 2024/25 data served for validation. Calibration results showed strong agreement with observed data, with normalized root mean square error RMSEn below 10% for all variables. Validation across stations produced R² values between 0.74 and 0.97 and RMSEn from 2.89% to 19.77%, confirming the model's reliability in simulating wheat (Triticum aestivum L.) growth and yield. Using the validated model, climate change impacts were evaluated under baseline (1991–2022) and future scenarios (SSP4.5 and SSP8.5 for the 2050s and 2080s). Simulations indicated notable cultivar- and location-specific yield responses, with most stations showing declines under SSP8.5 by the 2080s. At Degem, yield reductions of 9.75%–38.85% were projected for the Triticum aestivum L. ‘Wane’ cultivar under SSP8.5. Bishoftu showed declines for both Wane and Dendea, particularly under SSP8.5 in the 2080s, while Fitche recorded a 2.66%–6.5% decrease for Wane in the same period. Adaptation analysis under SSP8.5 revealed that delayed planting improved Wane performance at Degem, and late-maturing cultivars were better suited to Degem and Fitche. However, at Bishoftu, neither planting adjustments nor cultivar selection mitigated yield losses, underscoring the need for integrated adaptation approaches. Future studies should incorporate multi-model comparisons, broader adaptation options, and socioeconomic considerations to ensure sustainable wheat production in Central Oromia under climate change.

Pennycress (Thlaspi arvense) and camelina [Camelina sativa (L.) Crantz] are winter oilseed crops that can be implemented in cropping systems of the US Midwest region. Incorporating winter oilseed crops into the cropping system offers ecosystem and productivity benefits when the ground is otherwise fallow. However, adding a new crop into an established cropping system may increase pest or pathogen risk. Pennycress and camelina have been identified as a host and non-host, respectively, of the soybean cyst nematode (SCN, Heterodera glycines), a devastating soybean pathogen. The objective of this experiment was to investigate whether adding winter pennycress or camelina to a soybean–corn rotation affected SCN population density. The experiment was a two-level facorial with a split-plot design that included SCN-susceptible and SCN-resistant soybean varieties as main plots and oilseed crops (pennycress, camelina, and fallow) as subplots conducted at three field locations in Minnesota. Throughout the study, the SCN-susceptible soybean treatment significantly increased SCN population density when compared to the SCN-resistant soybean treatment. There was no measurable effect on SCN population density when camelina or pennycress was included as a winter oilseed crop. The results indicate that camelina or pennycress can be grown as winter oilseed cover crops in the soybean–corn rotations without significant risk to soybean production concerning SCN in Minnesota.

A comprehensive understanding of the interaction between genotype and environment at the local level, coupled with the development of effective management strategies, is imperative to meet the demand for maize (Zea mays) in Santa Catarina, Brazil, and elsewhere. This study estimated maize yield potential, water-limited yield potential, and yield gaps in the state. The study also identified the key biophysical and management factors contributing to yield gaps. The nine buffer zones selected encompass 63% of the total cultivated area dedicated to maize production. To ensure the appropriate balance between the quantity of data utilized and the representativeness of the study area, the Hybrid-Maize model and the method developed by the Global Yield Gap Atlas were employed. In the 2020–2021 and 2021–2022 agricultural years, surveys were conducted in 293 fields. A comparative analysis between high and low yields, in conjunction with regression tree analyses, enables the identification of management practices that warrant investment to elevate average yields and approach values approximating 75% of water-limited yield potential. The results indicated that the yield potential of maize in Santa Catarina is 17.4 Mg ha⁻¹, while the water-limited yield potential is 14.7 Mg ha⁻¹. Therefore, the attainable yield gap was estimated to be 4.0 Mg ha⁻¹. The primary management practices that constrain maize yield were identified, including the population of established plants, the rate of potassium fertilization, the sowing date, and the interval between lime applications. Improvements to these practices will enable an increase of 1.0 million Mg in the current crop area.

Cover crop mixes offer many benefits, including the management of herbicide-resistant weeds. In Southern cropping systems, summer mixes, planted after cash crop harvest and terminated by frost, can be valuable for effective weed management. In this 3-year study, four summer mixes were evaluated for their impact on weed suppression and the establishment of subsequent cash crops. Mix 1 had four grasses; mix 2 had two grasses, one legume, and one non-leguminous broadleaf; mix 3 had two grasses and two legumes; and mix 4 had two legumes and two non-leguminous broadleaves. Mixes 1, 2, and 3 produced the greatest biomass, thus offering the highest post-harvest weed suppression (>80% reduction in weed biomass) and moderate early-summer weed suppression, compared to fallow. The summer grasses sorghum-sudangrass (Sorghum bicolor × S. bicolor var. sudanense) and pearl millet (Pennisetum glaucum L.) were effective contributors to biomass production and weed suppression. Mix 4, with no grass component, still had a 54% reduction in weed biomass compared to the weedy check control. The corn and grain sorghum planted into the terminated legume mix plots showed enhanced growth, with none of the mixes negatively impacting these cash crops. In mixes 2 and 3 that contained legumes, corn plants were 18% taller on average and had 29% greater early-season plant biomass than the weed-free check. Overall, the findings suggest that summer mixtures, particularly those dominated by grasses, provide substantial weed suppression, with grass–legume combinations offering additional benefits to early cash crop performance.

Nitrogen (N) use efficiency on claypan soils is often low; therefore, adopting effective management practices is crucial for increasing corn (Zea mays L.) productivity and maximizing economic returns. The objective of this 4-year field study (2019–2022) was to evaluate the impact of anhydrous ammonia (AA) with or without a nitrification inhibitor (nitrapyrin) on corn productivity, grain quality, partial factor productivity (PFP), and economic returns across different topographic positions (shoulder, backslope, and footslope) within a landscape. Averaged over the years, AA + nitrapyrin treatment had over 6.4% yield advantage compared to AA alone. Grain N removal was 11 kg ha⁻¹ higher and PFP was 3.6 units higher with AA + nitrapyrin compared to AA treatment. Although the expected net returns with nitrapyrin were lower at the footslope and higher at the shoulder position, the incremental yields, economic yield difference, and net economic gains at the footslope were consistently greater than those at the backslope and shoulder. Averaged over site-years, the footslope position generated higher net economic gains ($200.07 ha⁻¹), which were $46.04 and $125.37 ha⁻¹ higher than the backslope and shoulder positions, respectively. These findings emphasize the importance of site-specific N management with nitrapyrin for optimizing yields, enhancing nutrient use efficiency, and maximizing economic returns under varying landscapes.