Agronomy Journal最新文献

The Ohio Corn Performance Test (OCPT) aims to provide farmers, educators, agronomists, and seed companies with information to help growers make decisions regarding hybrid selection and increase overall crop productivity. For more than 50 years, the OCPT has evaluated the agronomic performance of commercially available corn hybrids across the state. The objective of this study was to highlight overall trends as they relate to crop management, agronomic performance, and grain yields. The program has been planted annually at about 10 distinct sites grouped in three regions: Southwest/West Central Region, Northwest Region, and North Central/Northeast Region. Data collection and measurements include crop emergence percentages, lodging ratings, grain moisture, volumetric grain weight, and grain yields. Over the last 50 years, more than 53,000 hybrid combinations (i.e., hybrids × environments × years) were tested in the OCPT. From 1972 to 2021, seeding rates increased from 68,259 to 89,239 seeds ha⁻¹, seedling emergence increased from 86.2% to 94.9%, and final plant stands increased from 58,559 to 84,649 plants ha⁻¹. From these trends, the number of days from planting to harvest decreased by 11.5 days (slightly later planting dates, variable harvest dates), grain moisture at harvest decreased by 48 g kg⁻¹, and average volumetric grain weight increased by 83 kg m⁻³. The same period had a grain yield gain of 0.135 Mg ha⁻¹ year⁻¹, with 9.09 Mg ha⁻¹ in 1972 and 16.97 Mg ha⁻¹ in 2021 (an 87% increase). Overall, the annual OCPT results show agronomic and yield improvements that have contributed to the selection of hybrids in the state of Ohio.

Soybean [Glycine max (L.) Merr.] is the major source of protein for livestock and poultry feed in many countries including the United States. The United States is the second largest exporter of the soybean in the world. Although soybean yield in the United States has gradually increased over the past few decades, a consistent decline in seed protein concentration during the same period has occurred. As a result, soybean meal produced from some US seeds fails to meet the high-quality animal feed standards. Due to this trend, there is an urgent need to improve seed protein concentration to make US soybean competitive in the global feed market. This review article discusses the status of declining soybean seed protein concentration trend in the United States, its effect on soybean meal and animal feed quality and some potential solutions to promote soybean nutritional quality.

Goosegrass [Eleusine indica (L.) Gaertn.] is a difficult-to-control grassy weed occurring in compacted soils or heavy-traffic areas including golf greens. In Florida, goosegrass survives as a short-lived perennial, and eradication becomes more challenging as the plant matures. Currently, only foramsulfuron (FOR) is registered for postemergence goosegrass control in hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt-Davy] putting surfaces. A 2-year study evaluated the impact of three aerification treatments (none vs. once year⁻¹ or twice year⁻¹) followed by herbicide applications (FOR at 0.029 kg ha⁻¹, simazine at 0.525 kg ha⁻¹, metribuzin at 0.210 kg ha⁻¹, topramezone [TOP] at 0.006 kg ha⁻¹, and mesotrione [MES] at 0.175 kg ha⁻¹) to control mature goosegrass in a TifEagle hybrid bermudagrass putting green in Davie, FL. The impact of immediate post-herbicide irrigation on turf safety was also investigated. Aerification treatments were initiated in June, and herbicides were applied approximately 1 week after each aerification event. FOR did not effectively control goosegrass, while tank-mixes of mesotrione + topramezone tank-mix and simazine + mesotrione tank-mix provided effective control but produced unacceptable phytotoxicity. Post application irrigation reduced turf injury with TOP and MES alone in 2021, and weed control in both years. Aerification did not influence goosegrass control or turf safety.

Nitrogen (N) is an essential plant nutrient, but low and variable plant-available N levels in agricultural soils often limit maximum grain production. The objective of this study was to determine if a free-living nitrogen-fixing bacterial inoculant (NFI) could supply biologically-fixed N as an additional N source and if this enhances maize (Zea mays L.) N uptake and grain yield. Maize was grown at four site-years in Illinois during 2019–2021. The NFI, a mixture of edited Klebsiella variicola and Kosakonia sacchari, was applied in furrow at planting with urea-N rates from 0 to 225 kg N ha⁻¹. Using quadratic regression models, across N rates, the NFI supplemented the fertilizer-N equivalent of 38.5 or 12.1 kg N ha⁻¹ at V8 or R1, respectively. Increases in N accumulation were observed in all plant fractions, and δ¹⁵N abundance measurements confirmed that some of this additional N was derived from biological N fixation. The NFI treatment increased N accumulation by an average of 4.8% and 3.7% at V8 and R1, respectively, which was the result of greater biomass, with no effect on plant N concentration. Application of NFI resulted in an average of 1.5% more kernels m⁻² and 0.11 Mg ha⁻¹ more grain yield. This work reveals that NFI can provide an additional source of N for maize production but identifies that the season-long benefit of fixed-N from an NFI is yet to be fully optimized.

Potato (Solanum tuberosum L.) production is hindered by several diseases, the worst being the late blight disease caused by Phytophthora infestans (Mont) de Bary. This study aimed at determining an appropriate frequency of ametoctradin + dimethomorph ([26.9 + 20.2]%) spray for late blight disease management in potato genotypes. Field experiments were conducted in Bansoa, Cameroon, from August to October in 2019 and 2020 growing seasons The experimental design was a split-plot design with three replications. Three ametoctradin + dimethomorph spray frequencies (4-, 7-, and 10-day intervals) were tested at the plot level, whereas seven genotypes including Banso, CIPIRA, Desiree, Dosa, Jacob2005, Manate, and Tezelfo were tested at the subplot level. The commonly used fungicide combination, which includes Mancozeb 80% wettable powder supplemented with cymoxanil + chlorotalomil [(30 + 6)%] wettable powder, was sprayed at 3-day intervals (a total of 18 sprays) and was used as a positive control. Negative control plots were not sprayed. Data were collected on late blight rAUDPC (relative area under the disease progress curve) and yield components. Results showed all fungicide spray frequencies reduced rAUDPC and consequently increased potato yield. The most economically efficient spray frequency was the 7-day interval with a total of nine sprays, which resulted in an increased net return of $9738 ha⁻¹ with 9.6% profitability against the commonly used fungicide mix. The total number of fungicide sprays could be reduced to six for genotypes Banso and CIPIRA, which showed lower rAUDPC. The mean yield loss associated with unsprayed plots was 93.2%.

Recycling woody biomass for application to croplands is one option to divert materials from landfills and simultaneously improve degraded soil properties. Considering the diversity of materials that vary widely in characteristics, an understanding of the comparative effects of a single or combined application of these byproducts is missing with regards to soil C accumulation and availability of base and metallic cations. A field study was conducted in Québec City, QC, Canada, to assess the effects relative to untreated control of wood ash (10 and 20 Mg dry wt. ha⁻¹), pine biochar (10 Mg dry wt. ha⁻¹), papermill biosolids (12 Mg PB dry wt. ha⁻¹), and a combination of wood ash and PB on soil C, pH, and cations in a circumneutral loamy soil. The site was cropped to a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation. All materials were applied before corn planting and the effects of treatment were followed over two growing seasons. Applying wood ash resulted in the statistically largest increases (p < 0.01) in soil pH, percentage base saturation, and Mehlich-3 K, Ca, Mg, Zn, and Cd. Wood ash also increased K concentration in straw and total K accumulation for both plants, but its effect on plant metallic cations was limited. With a single application, PB only increased Mehlich-3 Ca with no further effect when combined with wood ash, while pine biochar was limited to sequester soil C. Therefore, this study indicated that wood ash could benefit a corn–soybean rotation by enhancing soil quality and crop yield.

Rejuvenating thinning alfalfa (Medicago sativa L.) stands with additional forage species have been ineffective in boosting productivity. Research is needed to identify practical solutions to extend the life of declining alfalfa and increase forage production. A 2-year field study at the University of Wyoming James C. Hageman Sustainable Agriculture Research and Extension Center in Lingle, WY, investigated the interaction effect of K and harvest time on thin alfalfa stands. Treatments were (a) six K rates (0, 56, 112, 168, 224, and 280 kg K₂O ha⁻¹ year⁻¹) applied to a ∼10-year-old alfalfa in the fall of 2019 and after the final harvest in the fall of 2020, and (b) two harvest times (early harvest, late bud to early [10%] bloom; late harvest, 7–10 days after early harvest), arranged in a 6 × 2 factorial under random complete blocks with four replications. Results showed a higher yield response to K at 224 kg K₂O ha⁻¹ year⁻¹ and early harvest, and at 168 kg K₂O ha⁻¹ year⁻¹ and late harvest particularly in soils with high soil test K levels (>300 mg kg⁻¹). Harvest timing influenced alfalfa's K needs, with quadratic responses of forage accumulation to K rate observed at early (p < 0.001, R² = 0.96) and late (p < 0.001, R² = 0.84) harvests. The 168 kg K₂O ha⁻¹ year⁻¹ increased stem density, increasing forage accumulation and profitability under both harvest systems. Stem density significantly impacts weed competition and stand productivity, with stem counts above 590 m⁻² maintaining optimal yields. Alfalfa producers worldwide, particularly in Wyoming and similar environments, can rejuvenate depleting stands by applying moderate K rates (∼168 kg K₂O ha⁻¹ year⁻¹) and adopting early or late harvest strategies when stem densities fall below ∼430 m⁻². However, when stem counts remain above this threshold and weeds are well managed, continued harvesting may be an efficient strategy.

Biofertilizers offer a sustainable alternative to chemical fertilizers, notorious for their harmful impact on the environment and human health. Sources of biofertilizers include cyanobacteria, such as those from the genus Arthrospira, which contain bioactive compounds that enhance plant growth directly and indirectly. To promote widespread biofertilizer adoption, experimental trials are essential to compare their efficacy against chemical fertilizers and different biofertilizer varieties. Some biofertilizers rely on ultrasonication for cell rupture, but since A. maxima undergoes sun-drying to obtain the biomass powder, which also ruptures cells, ultrasonication may be unnecessary. We assessed the biofertilizer capabilities of Arthrospira maxima (Setchell & N.L. Gardner) Geitler biomass on three cash crops, banana (Musa acuminata Colla), cowpea (Vigna unguiculata L. Walp.), and eggplant (Solanum melongena Mill. Dunal). We compared sonicated and non-sonicated biomass (both 20 g L⁻¹) against a commercially available, brown algae Ascophyllum nodosum (L.) biofertilizer (4 mL L⁻¹ OptiMar), a commercially available chemical fertilizer (1.5 mL L⁻¹ Triple15), and a negative control of tap water. Few differences were observed among A. maxima treatments, suggesting sonication might be unnecessary. OptiMar, Triple15, and the negative control did not yield the highest biometric values of any trait in any crop. If commercially available fertilizers and biofertilizers do not outperform the negative control, it raises crucial questions regarding their effectiveness and the appropriate concentrations at which they should be applied. Non-sonicated biomass often outperformed OptiMar, Triple15, and the negative control, demonstrating the potential Arthrospira maxima has for stimulating plant growth without ultrasonication.

Microorganisms can have a substantial effect on labile phosphorus (P), which may be lost from the soil surface and impact water quality. Changes in nutrient availability and soil health from agricultural management can affect microbial biomass carbon (MB-C), microbial biomass phosphorus (MB-P), and the expression of P cycling enzymes. The objective of this research was to investigate biological mechanisms affecting P availability and potential loss to runoff in a no-till, corn (Zea mays)–soybean (Glycine max) cropping system with two cover crops (cover crop [CC] and no cover crop [NC]) and three P management treatments (fall broadcast [FB], spring injected ammonium polyphosphate [SI], and no phosphorus application [NP]). Treatments were applied to a randomized block design with three replicates. Soil samples were analyzed for MB-P, MB-C, phosphatase activity, and Mehlich-III P (P_M). The P supply to the soil solution was measured using diffusive gradient thin film P (P_DGT). In Spring 2018, Fall 2018, and Spring 2019, all phosphatase activity was greater in CC versus NC (p < 0.01). Microbial biomass C was greater in CC compared with NC in spring but not fall samplings. On average, MB-P was fivefold greater in the P fertilized than unfertilized treatments (p < 0.001). CCs did not change MB-P, P_M, or P_DGT within FB or NP, but did affect SI fertilizer treatments. Our results suggest CC can increase potential for organic P mineralization, application of P fertilizer increases MB-P, and an interaction between SI P fertilizer management and CC may increase P supply to the soil solution.

Cassava (Manihot esculenta Crantz) was declared the “crop of the 21st century” by the Food and Agriculture Organization of the United Nations due to its high starch content and low input requirements. The management factors that govern yields and starch content in cassava in Brazil are still unclear. The aim of this study was to identify the main factors that limit the yield and starch content of cassava fields in Brazilian Cerrado. The data were collected as part of a survey covering 300 cassava fields in two growing seasons (2020–2021 and 2021–2022). Throughout the development cycle, management practices, yield, and percentage starch content in the roots were described. The database was divided into high and low yield tertiles. Mean comparison tests, regression tree analyses, and boundary functions were applied. The importance of genetics, environment, and associated crop constraints on cassava production (yields and starch content) was assessed. The yield gap in cassava was 44.6 Mg ha⁻¹. The most important factors leading to yield and starch losses were variety, planting date, and potassium fertilization. By adapting optimal practices, it is possible to produce an additional 1.5 million tons of cassava on the current cultivation area in the western Brazilian Cerrado, which corresponds to 8.3% of total production in Brazil and could increase the production of cassava starch by more than 400,000 Mg.