Agrosystems, Geosciences & Environment最新文献

Various agricultural crops are the world's sources of food, fodder, and energy. However, conservation management and diversification constraints remain a challenge. Therefore, the present study aimed to assess the status of local agricultural sorghum genetic diversity and potential determinants of the Wollo lowlands in northeastern Ethiopia. The greatest extent of local sorghum abundance was demonstrated in the study areas with the highest value being 4.25 D_Mg and 2.89 D_Mn in Werebabo district. However, 2.97 D_Mg and 2.04 D_Mn were recorded as the relatively lowest indices in Tehuledere province. In fact, the extent and type of diversity, measured by the number of varieties per farm, varied from region to region. Farmer perceived constraints such as late maturity, blending fluency, distance to nearest market (km), small land ownership, end-use quality, and plume size attributed to these deviations. The priority of the constraints was first determined by ranking the constraints based on the answers received from the respondents and then calculating the rank-based quotient. Several categorical variables of these constraints also showed a significant association with the status of local farm sorghum genetic diversity at p < 0.05 and p < 0.001. In general, the status of genetic diversity of local sorghum farms was low in all the provinces studied. Therefore, the seed exchange network between local farmers should be encouraged to use and conserve diversity on a daily basis. Community seed banks should also be established to enhance the conservation of beneficial local sorghum germplasm and maximize locally adapted sorghum landrace profiles.

Leguminous-based intercropping, combined with conservation agriculture, is a promising approach to improve soil fertility, crop yields, and sustainable land use for smallholder farmers in sub-Saharan Africa, including Malawi. This study aimed to assess the effects of incorporating legume-based intercropping systems involving pigeon pea (Cajanus cajan) and cowpea (Vigna unguiculata) into the deep bed farming (DBF) system promoted by Tiyeni in northern Malawi. The study used a split plot design with cropping systems (CS) as the main plots and tillage systems (TS) as the sub-plots. All treatments were replicated three times. The study encompassed two cropping seasons, where CS included legume-based treatments, sole cropped maize (Zea mays) without fertilizer (MZ) and sole cropped maize with 92 kg top dressing N fertilizer per hectare (MZ + 92), while TS included DBF and conventional tillage (CT). The study found that all plots with leguminous crops on both DBF and CT showed higher levels of ammonium (NH₄⁺), nitrate (NO₃⁻) and phosphorus (P) in the soil, but DBF had significantly higher levels over 2 years. Intercropping systems showed higher land productivity (land equivalent ratio > 1) than sole cropping in both years, indicating that legume-based cropping can improve land use efficiency and yields. It can be noted from this study that intercropping systems based on cereals and legumes, implemented in DBF, has the potential to sustain agricultural intensification in sub-Saharan African countries where access to chemical fertilizers is limited among smallholder farmers.

Wheat (Triticum aestivum L.) is one of the most important strategic crops to overcome food security problems in the world including Ethiopia. This can be achieved through genetic improvement of the crop and its production practices. In this connection, information on the mutual association of traits is important for effective selection in wheat-breeding programs. In 2021/2022 production year, a field experiment was undertaken to estimate the extent of genetic variability, path analysis, and association of yield and yield-related characteristics for the selection of desirable wheat genotypes. A total of 64 bread wheat genotypes, including yellow rust-resistant Boru (resistant), Hachalu (moderately resistant), and Madda-Walabu (susceptible) as control, were used for the field experiment at Sinana and Agarfa Agricultural Research Centers. The experiment was laid out in a simple alpha lattice design. The mean analysis of variances showed highly significant differences (p < 0.001) for all traits among the tested genotypes. The value of the phenotypic coefficient of variance was higher than the genotypic coefficient of variance for all studied traits, indicating the presences of higher genetic variability among the tested genotypes. Grain yield had a significant positive correlation with days to maturity, grain-filling period, plant height, kernels spike⁻¹, thousand seed weight, and biological yield at both genotypic and phenotypic levels including spike length at phenotypic levels at both locations and with plant height, thousand seed weight, and biological yield at both locations at genotypic and phenotypic levels. Similarly, days to maturity and grain-filling period also showed a significant positive phenotypic correlation with grain yield. The analyzed path coefficients at both genotypic and phenotypic levels also indicated how grain yield is influenced directly and indirectly by other yield and yield-related traits. The result also showed the existence of good heritability values along with high genetic advance, higher phenotypic coefficient of variation and genotypic coefficient of variation for grain yield, biological yield, and grain-filling period. This implies the true relationship among these traits and grain yield; therefore, due attention should be paid to such traits during selection for further improvement. Hence, the present study indicated the importance of the direct and indirect effects of the studied traits on yield and yield components which makes selection desirable for improving the grain yield of wheat and its genetic resistance against yellow rust in the study area.

Continuous land disturbance could negatively impact microbial community, but perennial crops can potentially reverse this negativity. The objective of this study was to evaluate the effects of Kernza (Thinopyrum intermedium) and alfalfa (Medicago sativa L.) on soil microbial structure and stress condition using the phospholipid fatty acid profiling. The study was conducted at the Ross Jones Research Farm, University of Missouri and consisted of four treatments: Kernza fertilized, Kernza unfertilized, Kernza and alfalfa intercrop, and alfalfa monocrop with four replications. Treatments were established in September 2021 on 18.3 m × 18.3 m plots. Soils from 0- to 5-cm and 5- to 15-cm depths were sampled in September 2021 (before treatments were placed) and 2022 and analyzed for microbial communities. All microbial communities increased after 1 year with the perennial crops. Since differences were not significant among treatments in 2022, this may lead to positive impacts of perennial crops on microbial communities, irrespective of the crop species and management. Moreover, community structure modifications were also observed with the perennial crops, irrespective of the species and management, as evidenced with changes in bacterial community indices in 2022. While fungi/bacteria ratio increased, Gram-positive/Gram-negative bacteria ratio decreased in 2022, suggesting a reduction in microbial stress, which can be attributed to ecological functions of the perennial crops. The study showed improvements in soil microbial biomass and modifications in microbial community structure after 1 year of Kernza and alfalfa. As the system matures, relative benefits of management (fertilization and intercropping) and plant species may be realized.

In Ethiopia, wheat variety development has traditionally prioritized yield and disease resistance over bread-making quality. To address this gap, our study evaluated 22 Ethiopian bread wheat varieties across six locations during the 2015/2016 season, utilizing a randomized complete block design with three replications. Various quality traits, including 1000-kernel weight (TKW), hectoliter weight (HLW), Perten hardness index (HI), single kernel weight (SKW), single kernel diameter (SKD), grain protein content (PC), wet gluten (WG), Zeleny value (ZV), and starch content (SC), were analyzed. Significant effects of varieties, locations, and their interactions on these traits were observed (p < 0.01). Madawalabu, Danda'a, and Mekelle-4 displayed superior TKW (>40 g), while Menze and Bolo exhibited higher HLW. HI values ranged from 82.8% in Sofumar to 35.5% in Mekelle-3, indicating diverse grain hardness. Favorable milling traits were observed with SKW values exceeding 30 mg and SKD surpassing 2.5 mm. Genotype and location influenced PC (9.5%–11.0%) and WG content (21.6%–25.2%), meeting bread-making requirements. ZV ranged from 21.9% to 31%, and SC varied from 64% to 68%, reflecting changes in starch concentration between varieties. Varietal performance varied, with Madawalabu, Menze, and Bolo showing promise. Correlation analysis revealed positive associations among HLW, SKD, SKW, TKW, PC, WG, and ZV, and a negative correlation with SC. These insights provide a foundation for targeted breeding strategies to enhance specific attributes crucial for optimal bread quality, contributing valuable information to wheat breeding programs.

Conservation agriculture (CA) aims to sustain agricultural production, soil, and environmental health in agroecosystems and has been promoted throughout the United States. The adoption of CA in cotton (Gossypium hirsutum) systems provides both agronomic and environmental benefits. Yet, there is limited information on the long-term effects of CA practices on crop yield and adaptation strategies. An integrated CA system, that is, cover crops with no-tillage (NT) instead of conventional agriculture, was implemented in the long-term field experiments and assessed with an integrated biogeochemical model. Using the denitrification–decomposition model, this study estimated the effects of four different cover crops, for example, native grass (NG), hairy vetch (Vicia villosa), winter wheat (Triticum aestivum L.), and crimson clover (Trifolium incarnatum), on cotton yield under four different nitrogen (N) levels (e.g., 0, 50, 100, and 150 kg N/ha) and estimated responses on carbon (C) sequestration, and ecosystem functionality over a 10-year study. The NT-NG 50 N was used as a calibration dataset to accurately estimate the cotton lint yield with a normalized root mean square error (NRMSE) of 21% and model efficiency of 0.3. The calibration data validated the effects of hairy vetch, winter wheat, and crimson clover under the NT-50 N with NRMSE of 24%, 21%, and 25%, respectively. According to the scenario analysis, the 50 kg N/ha application with a single-irrigation event (10-cm depth) was most beneficial for maximizing the cotton yield with cover crop incorporation at the NT system over the long term. The effects of increasing cover crop biomass (i.e., double seed rate) on C content, regardless of N application rates, varied based on the relationship between the main and cover crop species. Besides, the furrow plow tillage system provided efficient C sequestration. The proposed approach stands to provide agricultural and environmental sustainability with the implementation of cover crop or crop residue incorporation instead of increased N application, seed rates, and irrigation events under NT practices.

Carbon (C) amendments can enhance crop productivity, particularly in semiarid regions. Understanding the potential interference of C amendment with herbicide efficacies is essential to informing the practice. An experiment was conducted in western Nebraska in 2016–2018 to evaluate the effects of coal combustion residue (CCR) and herbicides on crop yields and weed density in the dry bean (Phaseolus vulgaris L.)–maize_db (maize [Zea mays L.] following dry bean)–sugarbeet (Beta vulgaris L.)–maize_sb (maize following sugarbeet) rotation. All crop phases of the rotation were present each year and received CCR at varying rates (0, 3.3, 6.6, 13.1, and 19.7 Mg C ha⁻¹) in spring 2016. Overall, CCR did not have consistent beneficial effects on crop yields. There were trends for yield benefits with CCR application compared to no-CCR plots in dry bean (p = 0.066) and sugar beet (p = 0.155) in 2017 and maize_db in 2018 (p = 0.222). In 2016, among no-herbicide treatments, the treatment with the highest CCR rate had a greater maize_sb yield (16.2 ± 0.1 Mg ha⁻¹) than the rest of the CCR treatments, including the control. The CCR application did not adversely affect herbicide efficacy in weed control. However, in 2016, among plots where herbicide (saflufenacil + dimethenamid-p) was applied, the CCR treatment (6.6 Mg C ha⁻¹) had lower maize_sb yield than the control. Future research should consider factors such as application rates, methods, and timing to assess the potential adverse effects of C amendments on herbicide efficacies.

Cover crops are usually terminated prior to planting the cash crop; however, “planting green” is an alternative approach that allows growers to plant cash crop into an actively growing, green cover crop, which is then terminated after the establishment of the cash crop. The objectives of this study were (1) to determine whether planting soybean (Glycine max L. Merr.) into a standing cereal rye (Secale cereale L.) cover crop provides superior weed suppression compared to terminating cereal rye 2 weeks before soybean planting and (2) to evaluate an integrated effect of herbicide programs and cereal rye termination timing on Palmer amaranth (Amaranthus palmeri S. Watson) control, biomass, seed production, soybean grain yield, and benefit/cost ratio. Field experiments were conducted in southcentral Nebraska from 2020 to 2022. Preemergence (PRE) herbicide with 2 weeks after planting (WAP) termination of cereal rye provided >95% Palmer amaranth control in 2021 and varied from 88% to 98% in 2022 at 28 days after PRE. A PRE herbicide followed by (fb) late-postemergence (LPOST) herbicide with 2 WAP termination of cereal rye controlled Palmer amaranth 85%–92% in 2021 compared with 97%–99% control 28 days after LPOST herbicide application in 2022. Palmer amaranth density was higher with 2 WBP cereal rye termination compared with 2 WAP termination regardless of the herbicide program. PRE fb LPOST herbicide programs integrated with 2 WAP termination of cereal rye reduced Palmer amaranth seed production to less than 9100 seeds plant⁻¹ in 2021 and no seed production in 2022. In 2021, terminating cereal rye 2 WAP played an integral role in controlling and reducing the density of Palmer amaranth; however, it had noticeable impact on soybean yield compared to terminating 2 WBP. In 2022, hail and windstorm had a confounding effect on soybean stand and yield.

Agroforestry systems have grown significantly in popularity in Bangladesh during recent years due to their favorable effects on the environment and human health. These systems are essential for supporting sustainable agriculture because they increase diversity, improve food security, and provide revenue. This study's main objective is to show how agroforestry is a widely used ecological and climate-resilient practice in Bangladesh. The research explores investment analysis, adoption-influencing factors, and a strength, weakness, opportunities, and threats (SWOT) analysis of agroforestry practices. A total of 340 respondents were chosen for this extensive study using a multistage random selection technique. The results showed a discrepancy in practice, with farmers exhibiting a high degree of awareness but limited application. Financial analysis employing metrics such as benefit-cost ratio, net present value, and internal rate of return favored agroforestry, indicating its economic viability and potential benefits for adopters. Additionally, the adoption of agroforestry was found to be significantly influenced by a binary logistic regression model that highlighted several important features, including larger farm sizes, younger age groups, greater education levels, training experiences, frequent extension visits, and enhanced market access. The study also identified barriers to adoption, such as a lack of trained labor, poor technical assistance, and education. This thorough analysis clarifies the opportunities and constraints for agroforestry implementation in Bangladesh. It suggests broad adoption by means of focused training initiatives that empower farmers, provide observable advantages, and promote nationwide acceptance.

The low translocation rate of stem assimilates and lodging under high nitrogen conditions are major factors limiting the realization of the yield potential of rice. The objectives of this study were to (1) determine the characteristics of stem nonstructural carbohydrates (NSCs) translocation and lodging resistance in different types of rice varieties and (2) elucidate the responses of stem NSCs translocation and lodging resistance to reduced nitrogen (RN) input. Field experiments were conducted using four types of rice varieties with two nitrogen levels, including normal nitrogen (NN, namely, farmer's practice, 225 kg N ha⁻¹ for indica conventional and indica hybrid rice and 300 kg N ha⁻¹ for japonica conventional and indica–japonica hybrid rice in Jiangsu Province, China) and 20% RN (180 and 240 kg N ha⁻¹, respectively). The results showed that there were significant differences in the stem NSCs translocation and lodging index of the basal stem among different types of varieties; indica hybrid rice was the highest, followed by indica conventional rice and indica–japonica hybrid rice, while japonica conventional rice was the lowest. The high activities of α-amylase, β-amylase, and sucrose phosphate synthase may contribute to high stem NSCs translocation. Correlation analysis revealed that NSCs translocation was significantly positively correlated with 1000-grain weight, grain yield, and lodging index, while it was significantly negatively correlated with dry weight/length, dry weight/volume, and bending stress of the basal stem. Compared with NN, RN significantly improved NSCs translocation and had no significant effect on the lodging resistance-related traits of the basal stem or grain yield. Therefore, this research indicates that a 20% reduction in nitrogen input can maintain grain yield by enhancing stem assimilate translocation without lodging resistance reduction and consequently synergizing nitrogen reduction, high yield, and lodging resistance.