Agrosystems, Geosciences & Environment最新文献

In sandy soils or areas with abundant rainfall, nutrients tend to leach from where plant roots grow. Nitrogen (N) is a mobile element that is consistently at risk of being lost to the environment. In the spring of 2023, a controlled-release fertilizer (CRF) study with two locations was undertaken at the North Florida Research and Education Center—Suwannee Valley (NFREC-SV) in Live Oak, FL. The objective of the study was to evaluate how broadcasting and banding CRF application methods (CRF-BAND and CRF-BROADCAST, respectively) influence snap bean yield, pod quality, soil nitrate-N, N uptake, and leaf tissue N concentration. The Caprice cultivar was evaluated using a randomized complete block design with four replications using an N rate of 112 kg ha⁻¹ at two trials with different planting dates. The results showed no significant differences in yield between methods of N fertilizer application or trials. Snap bean width was greater under CRF-BROADCAST and at Trial 2. Shoot N uptake increased more pronouncedly over time under CRF-BAND when compared to CRF-BROADCAST. Leaf N concentration remained similar across trials under CRF-BAND, indicating an effective shoot N uptake when N fertilizer is banded irrespective of planting dates. The results highlight the potential environmental benefits of banding N fertilizers, particularly in reducing nitrate-N leaching in sandy soils. The findings provide valuable information for developing more sustainable and environmentally friendly nutrient management techniques for snap bean cultivation.

Sugarcane (Saccharum spp. hybrid) manual planting in Florida faces challenges due to labor shortages. Even though mechanical planting offers potential benefits, concerns persist about its impact on soil-borne diseases and crop establishment. To address these concerns, two on-farm trials using split-plot design determine the effects of planting methods (mechanical vs. manual) and fungicide treatments (Priaxor, Provysol, Quilt Xcel) on sugarcane growth and yield. Data collected included seed cane rate, tiller dynamics, physiological parameters, plant height, gap analysis, and yield components across two growing seasons. Results showed mechanical planting required nearly four times higher rate of seed cane compared to manual planting. Mechanical planting reduced tiller count at early growth stage, but it was compensated at the later stage with no significant difference compared to the manual planting at the later growth stage. Significant interaction between planting methods and fungicide treatments in one of the two trials showed that fungicide application significantly improved plant height (by about 18%), number of millable stalks (by over 30%), and cane yield (by approximately 40%) in mechanical planting but not in manual planting. The physiological parameters, such as soil plant analysis development and leaf area index, were not influenced by planting methods or fungicide treatments. This study shows that switching from current manual planting to mechanical planting may need some changes in planting practice such as fungicide seed cane treatment at planting. Further research is needed to understand how mechanical planting may affect the planting practices, crop management, and farm economics.

Converting forests and grasslands to farms can impact soil properties and increase acidity. This study examines the effects of various land use types (LUTs) (cultivated, grazing, and forest) on soil characteristics and surface acidity in the Hula and Gorche districts of southern Ethiopia, analyzing 72 soil samples from six villages. The LUTs significantly influenced (p < 0.05) soil properties and acidity. Cultivated and grazing lands had higher sand content, bulk density, and levels of exchangeable acidity (EA) and acid saturation, but lower exchangeable bases and percent base saturation (PBS) compared to forest lands. In contrast, forest land had greater clay content, lower bulk density, and higher pH levels, indicating milder acidity. Total nitrogen and available phosphorus were also found to be lower in these areas. Soil organic carbon (SOC) levels were moderate in cultivated and grazing lands but high in forested regions. Significant correlations were identified in the chemical properties of the soil. Variations in soil SOC, cation exchange capacity, and PBS likely explain the differences in acid-buffering capacity across various land uses. The increased EA and lower pH in cultivated lands may enhance the availability of micronutrients, with soil acidity being a key factor that affects land use and micronutrient levels. The study recommends integrated strategies, including forest trees that enhance soil fertility and optimal agronomic practices, to manage soil acidity and fertility, aiming to increase crop productivity in regions facing similar challenges.

Chickpea (Cicer arietinum L.) is a vital pulse crop cultivated globally, especially in arid and semiarid regions. This study aimed to assess genetic variability, heritability, and interrelationships among yield and yield-related traits in 18 advanced chickpea genotypes using a randomized complete block design with three replications during the Rabi 2020–2021 season in Peshawar, Pakistan. Significant variation was observed for most traits, including seed yield, days to emergence, flowering, plant height, biological yield, and days to maturity, indicating enough genetic diversity among the genotypes. Moderate to high heritability estimates were recorded for key agronomic traits, suggesting the feasibility of genetic improvement through selection. Genotypic and phenotypic correlation analyses revealed strong positive associations of seed yield with days to 50% emergence, flowering, plant height, seeds per pod, days to maturity, and biological yield, which can serve as effective selection indices. Genotypes SL-03-29, MG5, and NDC-4-20-2 exhibited higher seed yields and are recommended for advanced yield trials and multilocation evaluations. Additionally, early-maturing genotypes such as NDC-15-01, NDC-4-20-4, and NDC-4-20-5 could be useful in breeding programs aimed at developing early maturing cultivars. These findings offer valuable insights for chickpea improvement and support the inclusion of stress-tolerance traits in future breeding programs.

Sweet corn (Zea mays L. saccharata) is a globally significant crop known for its unique biochemical profile and nutritional value. However, a yield gap in production exists in semi-arid regions. The overall goal of this work was to evaluate high-yielding, adaptable genotypes in regions with limited precipitation. The work was conducted in a semi-arid environment in northwest Iran. The research utilized 10 new inbred lines and 10 hybrids in a randomized complete block design with three replications during the 2023 growing season. The study evaluated a diverse range of morphophysiological and yield traits. The analysis of variance revealed highly significant differences among the studied genotypes, affirming the relevance of inbred lines and hybrids in sweet corn improvement. Based on the mean of parameters, five sweet corn inbred lines, namely, “SMRT-1,” “SWRY,” “SMRT-3,” “SPWRHDS,” and “SMRT-4,” along with two promising hybrids, “Merit-5 × Merit-3” and “Powerhouse × Merit-5,” exhibited superior responses in terms of all studied morphophysiological parameters as well as yield. The significant positive correlations found in this study and the high direct and indirect effects on yield measured in path analysis underscore the potential for the simultaneous selection of different traits in sweet corn breeding programs. The outcomes offer important insights into the relationships between traits and yield, paving the way for developing high-yielding sweet corn genotypes adapted to semi-arid regions. The implications of this research extend to regions with similar environmental conditions, offering the promise of enhanced food security and economic development through improved sweet corn production.

Maize (Zea mays L.) is an important food and nutritional security crop widely grown in Ethiopia. However, the crop yield is low due to low soil fertility, and erratic rainfall that results in moisture stress during the primary growing season. Field experiments were conducted in Haramaya district during 2019 and 2020 cropping seasons to investigate the effects of nitrogen (N) fertilizer rates and supplementary irrigation (SI) on maize productivity. The treatments consisted of six N fertilizer rates (0, 23, 46, 69, 92, and 115 kg N ha⁻¹) and (control or only rain-fed), and three SI levels (50%, 75%, and 100% crop evapotranspiration (ETc). The experiments were a split-plot design in a factorial arrangement. Irrigation was assigned to the main plots whereas N fertilizer rate was assigned to the subplots. The results indicated that the optimum grain (9.10 t ha⁻¹) and stover (12.02 t ha⁻¹) yields were recorded in response to the application of 69 kg N ha⁻¹ with 75% ETc SI. The grain and stover yields obtained at 69 kg N ha⁻¹ with 75% ETc SI exceeded the grain and stover yields obtained at nil N fertilizer rate with only rain-fed by about 356% and 144%, respectively. Furthermore, 75% ETc SI with 69 kg N ha⁻¹ resulted in the optimum (1.11 kg grain ha⁻¹ m⁻¹) water productivity. Therefore, it is concluded that under the early cessation of rainfall, 69 kg N ha⁻¹ with 75% ETc SI enhanced maize productivity in the study area.

Gebremichael, G. E., Bayratsion, Y. T., Abera, F. A., Egziabher, Y. G., Sbhatu, D. B., Tesfaye, K., Mekonnen, T., & Atsbeha, G. (2025). Genetic diversity and population structure analysis of Pisum sativum var. abyssinicum genotypes from Northern Ethiopia using ISSR markers. Agrosystems, Geosciences & Environment, 8, e70151. https://doi.org/10.1002/agg2.70151

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Genome-wide association study (GWAS) is a powerful method for understanding the associations between phenotype and genomic variations. Given the growing population, increasing yield of rice as a staple food crop is important. Here, a GWAS with 33,839 single nucleotide polymorphisms (SNPs) was carried out to define genomic regions influencing rice (Oryza sativa L.) yield components under field condition in 219 rice accessions using mixed linear model-Q-K model. High-throughput phenotyping provided extensive data for grain weight (GW), length and width, number of tillers, number of filled and empty grains per panicle, plant height (PH), panicle length, internode length, flag leaf length (FLL), and flag leaf width. Fifty five significant quantitative trait loci tagged to 97 SNPs were detected across all chromosomes of rice. Except for grain width, 3–10 genomic regions were identified for other 10 morphological traits. In the close vicinity of GWAS signals, well-known genes (such as SD1 for PH) were identified. Furthermore, the role of few recently reported genes that affect yield and its components were validated including monosaccharide transporter 1, nitrate transporter NTL1 (both associated with GW), and a sugar transporter family protein that is associated with grain length. Several novel candidate genes were detected by GWAS including the genes of glycoside hydrolase family, associated with tiller number, and growth-regulating factor 7, associated with PH and FLL. In addition, several transcription factors were identified for different traits. The findings of this research give new insights into the genetic improvement of rice yield and its components using genome-based breeding strategies.

Photoperiod-sensitive (PS) sorghum [Sorghum bicolor (L.) Moench] has been developed as a bioenergy crop. However, little is known about PS sorghum production in semiarid environments. The objective of this study was to investigate water use, biomass yield, and water-use efficiency (WUE) in recently developed PS sorghum genotypes. Field experiments were conducted in 2 years and two locations in the US Southern Great Plains. Six genotypes (TAM08001, TAM17500, TAM17600, TAM17650, TAM17800, and TAM18000) were grown in three water regimes (dryland, irrigation at 50% evapotranspiration (ET) demand, and irrigation at 100% ET demand). For both locations, soil water extraction (SWE) occurred at a 0–2.4 m profile in 2018 but at a 0–1.2 m profile in 2019. At Bushland, TX, biomass yield ranged from 4 to 31 Mg ha⁻¹ and seasonal ET ranged from 251 to 743 mm. In contrast, variations of biomass yield (10–19 Mg ha⁻¹) and seasonal ET (345–483 mm) were smaller at Colby, KS. The WUE in PS sorghum (3.19–4.09 kg m⁻³) did not differ among water regimes except for the dryland treatment (1.52 kg m⁻³) at Bushland (2018). The genotypic differences in SWE, biomass yield, ET, and WUE were more pronounced under dryland conditions. TAM08001, TAM17800, and TAM17600 had greater biomass yield and WUE under drought conditions. Overall, biomass yield levels of 10–17 Mg ha⁻¹ can be achieved in dryland in western KS, but under irrigation at 50% ET demand in the TX High Plains. Further studies are needed to better understand shoot and root traits related to drought tolerance in PS sorghum.

Soil physicochemical properties influence the efficacy of strategies for reducing ammonia (NH₃) volatilization from urea-based fertilizers, including fertilizer placement and the use of enhanced efficiency fertilizers (EEFs). Across the US Cotton Belt region, which spans the southern part of the country from Virginia to California and has various soil textures, little is known about how these strategies affect NH₃ volatilization. Studies were conducted as a randomized complete block design using four soils from this region to evaluate the impact of surface and subsurface placement of granular urea and fluid urea ammonium nitrate, as well as EEFs, on NH₃ volatilization. The EEFs were Environmentally Smart Nitrogen, N-(n-butyl)thiophosphoric triamide (NBPT) + Duromide, and nitrapyrin. NH₃ volatilization from surface broadcast urea without EEFs was 38%–62% of applied nitrogen (N) across soils and was greatest on the soil with the highest initial pH. Subsurface urea placement reduced NH₃ loss by 52%–80% compared to surface broadcast, and the greatest reduction was observed on the soil with the highest clay content. When urea was treated with NBPT + Duromide, NH₃ volatilization was reduced by 3%–76% compared to urea without NBPT + Duromide, and the lowest reduction was on the soil with the lowest initial pH. These results provide new insights into N management for some agriculturally relevant soils within the US Cotton Belt, which have previously been less evaluated for NH₃ losses. The findings can be used to tailor fertilizer application methods based on soil characteristics such as clay content and pH to minimize NH₃ volatilization.