Agronomy Journal最新文献

The effects of biochar and nitrogen (N) fertilization on soil carbon (C) and nitrogen (N) have been primarily studied in topsoil layers (0–30 cm), leaving a gap in understanding their long-term impact on deeper soil layers. This study investigates the effects of biochar (0 (B0) and 9 t ha⁻¹ year⁻¹ (B+)) and nitrogen fertilization (0 (N0) and 300 kg N ha⁻¹ year−1 (N+)) on soil organic carbon (SOC), soil organic nitrogen (SON), microbial biomass carbon, and microbial biomass nitrogen down to 150 cm. The study was conducted over 8 years in a rice field in northwest China. Results showed that biochar application increased total SOC by 27.0% and 12.2%, with and without nitrogen fertilization, respectively. Approximately 43.5%–51.8% of SOC was stored in the top 30 cm, while significant portions were found in deeper layers, indicating substantial carbon movement beyond the surface soil. Biochar also significantly increased SON in the 105- to 150-cm depth, regardless of N fertilization. These results suggest that failing to consider deep soil layers could lead to underestimations of soil C and N storage in paddy systems. The findings highlight the importance of biochar and nitrogen fertilization for improving carbon sequestration and nutrient cycling in rice paddies, offering insights into sustainable soil management practices.

A growing demand for herbal products is an opportunity for US growers to add diversity and high value crops into current rotations. Temperate tulsi (Ocimum × africanum) is a suitable crop for increased domestic production. In this study, we assessed how harvest frequency and harvest method influenced tulsi yield, quality, and total time to harvest. We assessed three distinct methods of harvest: (1) hand harvest, (2) mechanical harvest with a small plot combine, and (3) mechanical harvest with a swather. We paired these harvest methods with two levels of harvest frequency: a single cut per season and a double cut per season. This study was replicated in 2022 and 2023. We found no significant differences in tulsi yield when comparing hand harvest to either of the mechanical methods. Hand harvest took significantly more time compared to both mechanical methods. Quality was measured as eugenol content in dried plant material. Although eugenol means were higher overall in 2023, no clear trends emerged in the effect of harvest method or harvest frequency on eugenol content. Further research should explore how other agronomic practices can affect tulsi quality. The potential extension of this research to “true” tulsi, Ocimum tenuiflorum, and the inclusion of additional agronomic factors could help us better understand and optimize domestic tulsi production.

Soils and forages of Punjab, Pakistan, have mineral concentrations that are marginal for forage plant and animal requirements, and deficiencies of Ca can lead to economic losses. The efficacy of various Ca application methods for improving plant tissue Ca concentrations and forage productivity and nutritional value is not well defined. This field study was conducted in Punjab during 2021 and 2022 with the objective of quantifying the effects of Ca biofortification using seed coating or crop fertilization on forage responses of rhodesgrass (Chloris gayana Kunth.), an important regional forage. Treatments were the factorial combinations of two seed coatings (coated with 2 g CaSO₄ kg⁻¹ seed or non-coated) and nine CaSO₄ basal or foliar applications arranged in a randomized complete block design with three replications. The nine basal/foliar application treatments were no CaSO₄ (control), basal application of 1 Mg ha⁻¹ (B1), basal application of 2 Mg ha⁻¹ (B2), foliar application at 0.5% (F0.5), foliar application at 1% (F1), and B1 + F0.5, B1 + F1, B2 + F0.5, and B2 + F1. Seed coating increased plant height (2%), tillers plant⁻¹ (13%–16%), tillers m⁻² (15%–17%), leaf area (5%–7%), and dry matter harvested (DMH; 9%–13%) over no coating. Tillers plant⁻¹ and tillers m⁻² increased with increasing basal CaSO₄ application rate. Combining greater basal and foliar rates increased plant height (5.8%–8.3%), leaf area (9.6%–10.3%), and DMH (27.0–27.6). Tissue crude protein (33.0%–40.8%), digestibility (2.3%–2.5%), calcium (88%–92%) and sulfur (60%) concentrations also increased. Calcium biofortification using CaSO₄ as a basal and foliar treatment or as seed coating improved rhodesgrass DMH and nutritive value.

Ordóñez, R. A., White, C. M., Spargo, J. T., Kaye, J. P., Ruark, M., Iqbal, J., Shapiro, C. A., Thomason, W. E., Fiorellino, N. M., Thorne, L. A., Shober, A., Grove, J. H., Hirsh, S. M., Weil, R. R., Castellano, M. J., Archontoulis, S. V., Hatfield, J. J., Lee, C. D., Quinn, D. J., … Vyn, T. J. (2025). Delta yield predicts nitrogen fertilizer requirements for corn in US production systems. Agronomy Journal, 117, e70150. https://doi.org/10.1002/agj2.70150

There was an error in Figure 2c and Figure 4. In Figure 2c, the y-axis is labeled “Delta Yield (kg ha⁻¹)” and has been updated to “Delta Yield (Mg ha⁻¹).”

In Figure 4, the x-axis is labeled “Delta Yield (kg ha⁻¹)” and has been updated to “Delta Yield (Mg ha⁻¹).”

We apologize for this error.

Farmers are faced with many production decisions each season that greatly impact the profitability of their operations. Conducting on-farm trials can generate valuable insights regarding the benefits of new production practices or technologies, but the quality and reliability of the results hinge on trial design and analysis. Additionally, the impact of these findings is constrained by how widely the information is disseminated. In 2017, a team of Extension professionals at The Ohio State University launched the eFields program to enhance both the quantity and quality of farmer-participatory on-farm research in Ohio. In 2024, an evaluation tool was designed to understand how the eFields program has impacted the ways that farmers, agriculture professionals, and others engage in on-farm research and the information derived and shared from it. Growth in the program has been substantial, with a 478% increase in the number of trials completed each season and a 269% increase in farmer participation. Exposure to the program increased survey respondents’ likelihood on using on-farm research-based information for decision-making in their farm operations with 47.2% reporting they increased their use of these type of data. Participation in the program increased as farm size increased. Participating in on-farm research had a positive influence on farmer behavior changes; farmers who had conducted trials through the program were more likely to adopt new management or technology than farmers who only received information from the program. The information shared through the annual report is recognized as valuable to the target audience of farmers and agriculture professionals.

The study of relationships between traits is essential for understanding the behavior of variables of interest and advancing breeding programs. In popcorn (Zea mays L. var. everta (Sturtev) L.H. Bailey), popping expansion (PE) is considered the primary quality trait, but knowledge about the impact of agronomic traits and Fusarium spp. infection, known to directly damage grain integrity, is still limited. Thus, this study aimed to investigate the impact of a set of agronomic traits and Fusarium severity on popcorn PE. Four trials were conducted in Campos dos Goytacazes, Rio de Janeiro, Brazil. A randomized block design with three replications was adopted, evaluating 127 S₇ popcorn lines and collecting data on 14 variables. In each trial, phenotypic and genotypic correlations were estimated, and path analysis was performed using PE as the dependent variable. Correlations between kernel width (KW) × 100-grain weight (W100), number of leaves (NL) × number of leaves above the ear (NLAE), and grain yield (GY) × prolificacy (PR) were high and consistent. KW and severity of Fusarium ear rot (SFER) showed the strongest negative genetic correlations with PE (−0.48 to −0.66 and −0.50 to −0.71, respectively), with direct effects confirmed by path analysis. GY exhibited a positive direct effect on PE in most trials, while the low correlation between these variables was attributed to indirect effects. These findings highlight the potential of grain morphology and resistance to FER as selection criteria to improve PE and suggest possibilities for simultaneous gains through integrated selection strategies.

Optimizing phosphorus (P) management in potato (Solanum tuberosum L.) production while minimizing environmental impacts remains a significant challenge, particularly in sandy soils. This 2-year field study evaluated the effects of microbial biostimulants and varying P rates (0–112 kg P ha⁻¹) on potato yield, quality, P use efficiency, and soil P availability in Florida's sandy soil. The study employed a split-plot design with six P rates as main plots and biostimulant application as subplots. Results revealed that total and marketable tuber yields increased significantly with P application, with the highest responses observed at 90 kg P ha⁻¹. Marketable yield improved even in soils testing high in extractable P, underscoring that the extractable soil P does not reliably indicate plant-available P during early growth. P fertilization had minimal effects on specific gravity but increased pick-outs at higher rates. However, biostimulant application with the tested product did not significantly enhance tuber yield, quality, or P use efficiency across any P rate. P use efficiency indices declined with increasing P rates. The study revealed that while P fertilization remains crucial for potato production in sandy soils, the effectiveness of the microbial biostimulant may be limited under current management practices. These findings suggest the need for refined P management strategies that account for seasonal variations in soil P availability and site-specific environmental conditions to optimize potato production while improving P use efficiency.

Growing global livestock demand drives the need for efficient forage production systems that optimize productivity within ecological and resource limits. Integrating forage legumes with grasses could enhance soil health, forage yield, and nutritional composition. However, proper quantification of agronomic and short-term soil health benefits of legume-integrated forage cropping systems is limited, specifically in water- and nutrient-limited conditions of arid and semi-arid regions. This study (2021–2024) evaluated forage biomass accumulation, nutritive values, and soil health dynamics with and without alfalfa (Medicago sativa L.) interseeding into two bermudagrass (Cynadon spp.) varieties, Wrangler and Cheyenne II, in water- and nutrient-limited conditions of the semi-arid southern High Plains. Results indicated that the bermudagrass Cheyenne II monoculture produced the greatest dry matter forage yield in all years. Bermudagrass–alfalfa mixtures did not receive nitrogen (N) fertilizer, but in most cases, they had similar yields and improved forage nutritional value compared to bermudagrass monocultures. For example, compared to bermudagrass monocultures, the mixtures with alfalfa had 15%–25% greater crude protein, 24%–36% lower neutral detergent fiber, 32%–40% greater relative feed value, and 10%–16% greater relative forage quality. Soil organic carbon (C) and total N at 0- to 30-cm depth were similar across all treatments after 3 years of forage production. Selected soil health indicators monitored in the 2023 and 2024 growing seasons showed no differences among treatments. Integrating alfalfa into bermudagrass can enhance forage production efficiency and quality while minimizing the dependence on synthetic fertilizers, promoting a sustainable pathway to forage production in resource-limited conditions.

Root-derived carbon (C) and nitrogen (N) release in relation to chemical composition has rarely been quantified in field studies. The objectives of this study were to evaluate C and N release from six summer cover crop roots and to correlate it with their chemical composition. Root decomposition and N release from velvet bean (Mucuna aterrima), pearl millet (Pennisetum americanum), dwarf pigeon pea (Cajanus cajan), sunn hemp (Crotalaria juncea), showy rattlebox (Crotalaria spectabilis), and jack bean (Canavalia ensiformis) were evaluated over 2 years under no-till subtropical conditions. There was no difference in C release rates for either the labile or recalcitrant C compartments in the first (average: k₁ = 0.0577; k₂ = 0.0017) or the second year (average: k₁ = 0.1657; k₂ = 0.0029). Root C remaining after 140 days did not differ in the first year (average 46.4%), but it was higher in the second year for pearl millet (65.3%) compared to the other species (40.2%). N release was the most intense during the first 21 days and decreased drastically afterward. After 140 days, the N remaining in pearl millet and velvet bean roots was higher (77.7%) than in the other species (47.1%) in the first year, while in the second year, pearl millet contained more N (50%) compared to velvet bean (38%) and jack bean (28.1%). The C and N release rates were poorly correlated to the chemical composition of the summer cover crop roots. Our results reinforce the agronomic recommendation to sow main crops immediately after cover crop management to maximize N recovery from roots.

Nitrogen (N) is essential to maximize corn (Zea mays L.) yield; however, over- and underapplication can cause environmental concerns or yield losses. Optimizing N management is critical to balance productivity and sustainability. This study was conducted during 2022–2024 in Florida to determine corn N response. The experiment included six N rates (0–392 kg N ha⁻¹ by 78.5 increments) over 3 years, with an additional rate (471 kg N ha⁻¹) in the third year, using a randomized complete block design with four replications. Results showed that 314–471 kg N ha⁻¹ produced the highest and statistically similar aboveground biomass (21,598–23,166 kg ha⁻¹), grain yield (12,479–13,588 kg ha⁻¹), and N uptake (227–250 kg ha⁻¹). For grain N removal, (144–162 kg ha⁻¹), 392 and 471 kg N ha⁻¹ were statistically similar, while 314 kg N ha⁻¹ was significantly lower than 392 kg N ha⁻¹, indicating a threshold response beyond 314 kg N ha⁻¹. Agronomic N use efficiency and partial factor productivity were highest at 157 (58.8 kg kg⁻¹) and 78.5 (57.9 kg kg⁻¹) kg N ha⁻¹, respectively. Results suggest no agronomic advantage above the 314 kg N ha⁻¹ rate, and yield decreased at 471 kg N ha⁻¹. Response analysis indicated that 23.2 g N was required per kg of corn grain under irrigation system. The nitrogen nutrition index confirmed that moderate applications (235–314 kg N ha⁻¹) sustained crop N status, while higher rates (>392 kg N ha⁻¹) offered little to no benefit. Collectively, these results support refining N recommendations to optimize agronomic production in Florida.