Nitrous oxide (N₂O) emission from denitrification in agricultural soils often increases with nitrogen (N) fertilizer and soil nitrate (NO₃⁻) concentrations. Our hypothesis is that legume cover crops can improve efficiency of N fertilizer and can decrease N₂O emissions compared to non–cover crop systems. The objectives of this study were to (a) evaluate the performance of summer leguminous cover crops in terms of N uptake and carbon (C) accumulation following winter wheat and (b) to quantify the effects of summer leguminous cover crops and N fertilizer rates on N₂O emissions and grain yield of the subsequent grain sorghum crop. Field experiments were conducted in the context of a wheat-sorghum rotation for two seasons in Kansas. Treatments consisted of double-cropped leguminous cover crops following winter wheat harvest with no fertilizer applied to the following grain sorghum or no cover crop after wheat harvest and N fertilizer rates applied to the grain sorghum. The cover crops were cowpea (Vigna unguiculata L. Walp.), pigeon pea (Cajanus cajan L. Millsp.), and sunn hemp (Crotalaria juncea L.). The three N treatments (were 0, 90, and 180 kg·N·ha⁻¹). Fallow systems with 90 and 180 kg·N·ha⁻¹ produced significantly greater N₂O emissions compared with cropping systems that received no N fertilizer. Emissions of N₂O were similar for various cover crops and fallow systems with 0 kg·N·ha⁻¹. Among cover crops, pigeon pea and cowpea had greater C accumulation and N uptake than sunn hemp. Grain yield of sorghum following different cover crops was similar and significantly higher than fallow systems with 0 kg·N·ha⁻¹. Although fallow systems with 90 and 180 kg·N·ha⁻¹ produced maximum sorghum grain yields, N₂O emissions per unit of grain yield decreased as the amount of N fertilizer was reduced. We conclude that including leguminous cover crops can decrease N fertilizer requirements for a subsequent sorghum crop, potentially reducing N₂O emissions per unit grain yield and providing options for adaptation to and mitigation of climate change.

This study evaluates the effectiveness of stone bunds in enhancing soil moisture, vegetation health, and crop yields in Ghana’s semi-arid Upper East Region, an important area for agricultural productivity in West Africa. In this region, agricultural practices are heavily impacted by erratic rainfall and poor soil moisture retention, threatening food security. Despite the known benefits of traditional soil conservation practices like stone bunds, their effectiveness in this context has not been fully quantified. Field and remote sensing data were used to evaluate the influence of stone bunds on soil moisture dynamics, vegetation growth, and crop yield. Experimental plots with and without stone bunds were monitored for climate, soil water infiltration, and soil moisture and analyzed using the NDVI from Sentinel-2 satellite imagery over two growing seasons under sorghum production (2022–2023). The results indicated that stone bunds enhanced soil moisture retention and increased infiltration rates. The NDVI analysis consistently revealed higher vegetation health and growth in the plots with stone bunds, particularly during critical growth periods. The intermediate results of the conducted experiment indicated that stone bunds increased sorghum yields by over 35% compared to the control plots. The substantial agronomic benefits of stone bunds as a soil and water conservation strategy were evident, improving soil water infiltration, water retention, vegetation health, and crop yields. The findings support the broader adoption of stone bunds in semi-arid regions to enhance agricultural productivity and resilience against climate variability. Further research is recommended to explore the long-term impacts and the integration of stone bunds with other sustainable farming practices to optimize rainfed agricultural outcomes.

The economic return for peanut (Arachis hypogaea L.) in Ghana is often low due to limitations in the availability of inputs or their adoption, which are needed to optimize yield. Six experiments were conducted in Ghana in 2020 and 2021 to determine the impact of planting date, cultivar, fertilization, pest management practices, and harvest date on peanut yield, financial return, and pest reaction. A wide range of interactions among these treatment factors were often observed for infestations of aphids (Aphis gossypii Glover); groundnut rosette disease (Umbravirus: Tombusviridaee); millipedes (Peridontopyge spp.); white grubs (Schyzonicha spp.); wireworms (Conoderus spp.); termites (Microtermes and Odontotermes spp.); canopy defoliation as a result of early leaf spot disease caused by Passalora arachidicola (Hori) and late leaf spot caused by Nothopassalora personata (Berk. and M. A. Curtis); and the scarification and boring of pods caused by arthropod feeding. Pod yield and economic return increased for the cultivar Chitaochi and Sarinut 2 when fertilizer was applied and when fertilizer was applied at early, mid-, and late planting dates. Pod yield and economic return increased when a combination of locally derived potassium soaps was used for aphid suppression and one additional hand weeding was used in the improved pest management practice compared with the traditional practice without these inputs. Pearson correlations for yield and economic return were negatively correlated for all pests and damage caused by pests. The results from these experiments can be used by farmers and their advisors to develop production packages for peanut production in Ghana.