Effects of Integrated Acid Soil Management Approach on Soil Properties, Barley Yield and Yield Components in the Southern Highlands of Ethiopia
Abstract
ABSTRACT Soil acidity is a major constraint to barley production in the Southern Highlands of Ethiopia. An on-farm experiment was conducted during the 2020 and 2021 cropping seasons on strongly acidic Nitisols (pH 4.7) to evaluate the effects of integrated application of vermicompost (VC), inorganic nitrogen (N), and lime on soil chemical properties and barley productivity. Nine treatments, comprising a control, sole and combined applications of VC and N at different proportions, and integrated treatments with lime (3 t ha−1), were arranged in a randomized complete block design with three replications. Integrated application of VC, N, and lime significantly increased soil pH, available phosphorus, soil organic carbon, and total nitrogen while reducing exchangeable acidity compared with the control and sole nutrient applications. Grain yield and yield components were also significantly improved in both cropping seasons. The combined application of 50% VC + 50% N + 3 t ha−1 lime produced the greatest improvements in soil fertility and barley yield, indicating synergistic effects of integrating organic, inorganic, and liming materials for acidic soil management. The integrated application of 100 kg urea + 100 kg NPSB + 5 t vermicompost ha⁻¹ is recommended for farmers seeking to maximize barley productivity and overall profitability because it generated the highest grain yield and net benefit. However, for resource-constrained farmers with limited capital, the sole application of 100 kg urea ha⁻¹ is a practical alternative because it produced the highest marginal rate of return, indicating greater economic efficiency per unit of additional investment. Improved soil fertility and grain yield in the second cropping season demonstrated residual benefits of the integrated treatments. Overall, integrated use of vermicompost, nitrogen fertilizer, and lime was more effective than sole nutrient applications in improving soil fertility and sustaining barley production on acidic Nitisols.