Agrosystems, Geosciences & Environment最新文献

To sustain agriculture for future generations and reduce the adverse impacts on soil health and the environment, there is a need to adopt sustainable and climate-smart agricultural practices. A field experiment was conducted to study the effects of organic amendments (chicken and dairy manures and biochar) on the soil physicochemical properties, sweet corn (Zea mays) growth, and yield parameters at Prairie View A&M University, Texas. Two rates of biochar (2.5 and 5 t ha⁻¹) and two types of manure (chicken and dairy) applied at three rates (0, 224, and 448 kg total N ha⁻¹) were used in a factorial design with three replications. Plant height, period for each vegetative growth stage, leaf soil plant analysis development, time to reach 50% tasseling and 50% silking stage, cob length, cob diameter, sugar content, and biomass were measured. The results showed that plant biomass was significantly affected by biochar rate, while plant height, cob length, and cob diameter were significantly affected by manure rates. Sweet corn reached tasseling and silking stages earlier in chicken manure-treated plots than the dairy manure plots. However, the sugar content was significantly affected by both biochar and manure rates. Furthermore, results revealed a strong positive correlation between plant height and cob length, diameter, and biomass; however, there was a negative correlation with tasseling and silking days. Soil phosphorus, total nitrogen, and potassium had a relatively positive correlation with plant growth parameters. Findings showed that different types and rates of amendments significantly influenced sweet corn growth parameters and soil nutrient status, highlighting the importance of adopting climate-smart agricultural practices for improved crop yield and soil health.

This article presents an economic analysis of two phosphorus (P) fertilizer recommendation approaches, sufficiency and build-maintenance, in the context of Kansas and Oklahoma wheat (Triticum aestivum L.). Sufficiency seeks to meet crop needs rather than build soil fertility. Build-maintenance, however, builds P levels to a target level of soil test phosphorus (STP) and then maintains that level by replacing the P removed by the crop. The Oklahoma and Kansas sufficiency approaches recommend less P than their build-maintenance alternatives. The research objective was to determine when one approach is preferred over the other. Through dynamic simulation, the net present value (NPV) of these two alternatives was estimated under alternative scenarios. A meta-analysis of previous experiments supported the assumption that with Mehlich-3 STP levels of 15 mg kg^‒1, yield would be 90% of maximum yield even when the recommended sufficiency levels were applied. The estimate from the meta-analysis was a 9% yield loss, and the null hypothesis of no yield loss was rejected (p < 0.0001). The scenarios considered varied initial STP, yield potential, and prices. Sufficiency had a higher NPV under almost all 4-year planning horizons. With a longer 20-year planning horizon, build-maintenance was always preferred. With an 8-year planning horizon, the preferred system varied depending on assumptions with build-maintenance preferred more often. The finding of build maintenance being more competitive in the long run should hold for other crops and locations using approaches like those in Oklahoma and Kansas.

Increasing crop production in a changing climate is one of the challenges facing the agricultural research community. The goal of this study was to identify and evaluate specific determinant traits for improving water stress resiliency of cultivated upland cotton (Gossypium hirsutum L.). Two genotypes (PhytoGen 72 [PHY72] and Stoneville 474 [STV474]) representing different production regions of the US were evaluated for water stress resiliency under greenhouse conditions. More than 20 vegetative and reproductive traits were evaluated through six physiological reproductive stages, from plant emergence to open bolls and under two irrigation levels. Significant differences (p ≤ 0.05) were observed between irrigation levels for most traits within each genotype. PHY72 had rapid increases in plant height under regular water and limited water conditions (RW and LW). RW approximated daily evapotranspiration rates, while LW rate provided 50% less water by mass. However, by the fourth stage, peak blooming, the two genotypes were the same height, indicating that early and rapid vegetative plant growth from emergence to first reproductive stage was not a good indicator of improved growth and boll production under diverse irrigation levels. Some traits, such as leaf temperature, chlorophyll fluorescence yield, leaf and boll number, as well as leaf and reproductive fresh weight, showed clear differences between the two genotypes in one or both irrigation rates. Cotton breeders/geneticists currently cannot predict end-of-season productivity based on early-season evaluations under water stress conditions. Early season, controlled environment screening before field testing may reveal the genetic potential of breeding lines for water stress resiliency.

Knowing the accession's qualitative and quantitative genetic variability is the prerequisite for the trait's improvement for any barley (Hordeum vulgare L.) improvement programs. This study aimed to investigate the agronomic and yield trait performance. The field experiment was conducted in Gumer for the years 2021/2022 and 2022/2023 using the augmented block design with the data of 319 barley genotypes, including nine check entries and using eight blocks in rain-fed conditions. A total of 23 both qualitative and quantitative traits were measured. The chi-square test analysis showed significant genotypic variation for all qualitative traits. The significant differences (p < 0.001) in all the quantitative traits except for plant height, spike length, and harvest index. There was sizeable quantitative variation among the genotypes indicating the need to exploit a high degree of genetic variation through selection. The first four principal component analyses accounted for 64.82% of the total variation and the cluster analysis discriminated the barley into four discrete clusters. The correlation coefficient indicated significant differences among the correlations of the 10 quantitative traits. Furthermore, G6, G214, and G255 for earliness and G182, G126, and G44 for grain yield. Both qualitative and quantitative traits made it possible to locate potential new sources of genetic variation. Certain barley was thought to be possible sources of various agronomic traits, such as drought tolerance. The characterized Ethiopian landraces can be used to improve barley resilience against climate change and associated conditions and are recommended in breeding programs to improve productivity under different breeding objectives.

Assessment of the genetic variability is an important step in improving nitrogen (N₂) fixation potential of faba bean (Vicia faba L.) genotypes. The study was conducted to evaluate the genotypic variation for symbiotic N₂ fixation traits of faba bean under contrasting phosphorus (P) fertilizer regimes. Twenty and 12 genotypes in the field and greenhouse, respectively, were planted under two P fertilizer regimes (P− and P+ corresponding to 0 and 46 kg/ha) using a randomized complete block design with three replications. Analysis of variance indicated highly significant (p < 0.01) variation among genotypes for all N₂ fixation traits under both P regimes, indicating the availability of genotypic variation. Genotypes Obse, Dosha, Didea, Gebelcho, Gora, Moti, and Hachalu had better performance for N₂ fixation traits and higher grain yield (GY) across all study conditions. Performances of all N₂ fixation traits, except nitrogen harvest index, were better under P+ than under P−. P fertilizer application in the field resulted in 12.3, 12.9%, 18.9%, and 24.2% increase in the number of nodules per plant, nodule dry weight per plant (NDWP), N₂ yield (NY), and the amount of N₂ fixed (NF), respectively. In the greenhouse, 18.9%, 22.5%, and 27.2% increment was obtained for NDWP, NY, and NF, respectively, due to fertilizer application. Biplot analysis revealed that NF, NY, percentage of nitrogen derived from atmosphere (%Ndfa), shoot nitrogen concentration (ShN), and GY were the traits responsible for large genetic variation for N₂ fixation. NF had higher heritability and formed a significant positive correlation with most nitrogen fixation traits, suggesting the potential of the trait to be improved through breeding.

An experiment was conducted in the greenhouse facilities of Embrapa Maize and Sorghum to evaluate the limestone reaction in sandy soil based on rates, limestone type, effective calcium carbonate equivalent (ECCE), and moisture regime over time. A factorial design of 4 × 2 + 3 was adopted, consisting of four limestone rates with 76% ECCE (0, 1, 2, and 4 Mg ha⁻¹), two irrigation types (daily and monthly, simulating constant and intermittent moisture regime), and three additional treatments (three rates of “filler” limestone—99% ECCE—under monthly irrigation). Soil chemical characteristics were analyzed at 1, 2, 3, 6, and 12 months after treatment application. Soil fertility improved at the first month after treatment application, with emphasis on higher limestone rates, monthly moisture regime, and filler lime stone. The highest limestone rate did not increase the pH above 7.0. The recommended limestone rate was insufficient to elevate Ca + Mg levels to the adequate level for current production genotypes and systems, which demand higher standards. These outcomes reinforce the need for carrying out further studies and potential revision in liming recommendations for sandy soils.

Zoysiagrass (Zoysia spp. Willd.) is a popular choice for commercial and residential lawns, as well as golf course fairways and tees because it requires less light, fertilizer, and mowing compared to bermudagrass (Cynodon spp.). However, zoysiagrass' slow growth rate compared to other putting green options presents a challenge for both rapid establishment from sprigs and its wider adoption as a putting green surface. It is currently unknown if very frequent irrigation, commonly used in horticultural propagation, can be applied to turfgrass and accelerate establishment from sprigs. Irrigation was applied to Prizm zoysiagrass sprigs across either four or 192 irrigation events from 06:00 a.m. to 10:00 p.m. Prizm zoysiagrass establishment was unaffected by irrigation frequency and averaged 40% turfgrass coverage after 21.6 and 27.3 days in run A and run B, respectively. These results imply that very frequent irrigation did not accelerate establishment. Additional research elucidating zoysiagrass sprig physiology during propagation and development is necessary to better define management practices that hasten establishment.

Soil degradation is a worldwide problem, causing the declining performance of many plant species. Recently, the application of sediments dredged from aquatic waterways has received attention for their potential as an organic amendment to revive degraded agricultural soils. In Ohio, dredged sediment research has largely focused on the success of corn (Zea mays) or soybean (Glycine max) following the application of dredged sediments from the Toledo Harbor, neglecting the potential for dredged sediments from the other eight harbors and waterways to change plant performance as well as failing to quantify benefits for other commonly grown crops in the region. In a greenhouse experiment, we applied dredged sediments from the Lorain Harbor to degraded agricultural soils across a variety of application ratios and quantified changes in germination, height over the growing season, final biomass, and yield for canola (Brassica napus), tall fescue KY 31 (Festuca arundinacea), and corn to better understand the potential for dredged sediments from this location to increase performance for a variety of regionally important plant species. Overall, plants grown on agricultural soils supplemented with dredged sediments from the Lorain Harbor consistently grew taller, faster, and were larger than the 100% dredged sediment treatments. Furthermore, both corn and tall fescue grown on agricultural soil supplemented with dredged sediments had greater yield compared to their counterparts grown on unamended agricultural soil. In whole, outcomes from this research contribute to a growing body of research that support the use of dredged sediments as a soil amendment for agricultural soils.

The evolution and widespread occurrence of herbicide-resistant weeds pose a major challenge for farmers and crop consultants across North America, warranting integrated management strategies. The adoption of cover crops offer weed suppression and soil health benefits but adds management complexity. A survey, targeting farmers and crop consultants, was conducted during the spring of 2023 to evaluate current cover crop management practices and perceptions in Wisconsin cropping systems. The survey included 26 questions across five sections: respondent profile, cover crop adoption and experience, cover crop management ahead of soybean [Glycine max (L.) Merr.], cover crop management ahead of corn (Zea mays L.), and general benefits and challenges of cover crop adoption. Farmers and crop consultants represented most respondents, influencing a total of 29,500 and 557,000 ha, respectively. Waterhemp (Amaranthus tuberculatus [Moq.] J.D. Sauer) and giant ragweed (Ambrosia trifida L.) were identified as the most troublesome weeds. Over 90% of respondents use herbicides to terminate their cover crops, and 68% of respondents agree that cover crops improved overall weed control in their farms/clients’ farms to some extent [cereal rye (Secale cereale L.) as main cover crop species]. Additionally, results demonstrate a strong consensus (85%) on cover crops positively influencing water retention, with 98% agreement on their efficacy in reducing soil erosion. Results from this survey can help guide farmers, agronomists, researchers, and policymakers with cover crop adoption, management, policies, incentives, and future research and education needs in Wisconsin and beyond to support the development of more sustainable and efficient weed and crop management strategies.

Aerobic rice production offers a promising solution to improve water use efficiency and reduce methane (CH₄) emissions by minimizing water inundation. However, alternate water-saving methods for rice cultivation can lead to “trade-off” emissions of nitrous oxide (N₂O). A field experiment was conducted over one season measuring soil-derived greenhouse gas emissions in irrigated aerobic rice (Oryza sativa L.) under different N fertilizer management at a rate of 220 kg N ha⁻¹, including a nil treatment (“control”); slow release (180 days) polymer-coated urea (“N180”); banded urea applied upfront (“urea”); and three applications of broadcast urea (“urea-split”). The N180 treatment reduced soil N₂O emissions compared with urea (p < 0.001), with mean cumulative N₂O emissions of 4.36 ± 1.07 kg N ha⁻¹ and 27.9 ± 5.70 kg N ha⁻¹, respectively. Soil N₂O fluxes were high, reaching up to 1916 and 2900 µg N m² h⁻¹ after urea application and irrigation/rain events, and were similar to other irrigated crops grown on heavy textured soils. Fertilizer N management had no effect on soil CH₄ emissions, which were negligible across all treatments ranging from 1.28 to 2.75 kg C ha⁻¹ over the growing season. Cumulative soil carbon dioxide emissions ranged from 1936 to 3071 kg C ha⁻¹ and were greatest in N180. This case study provides the first evidence in Australia that enhanced efficiency nitrogen fertilizer can substantially reduce N₂O emissions from soils in an aerobic rice system. Our findings reinforce the CH₄ mitigation potential of water saving rice approaches and demonstrate the need to consider N fertilizer management to control N₂O emissions.