Integrated vermicompost and blended NPSB fertilizer enhances soil physicochemical properties and barley (Hordeum vulgare L.) productivity in the acidic highlands of Western Ethiopia.

内容摘要

Soil fertility depletion and acidity are major constraints to barley (Hordeum vulgare L.) production in the Ethiopian highlands. Integrated soil fertility management offers a sustainable solution, but site-specific recommendations are lacking for the Horro District. This study evaluated the integrated effects of vermicompost (VC) and blended NPSB fertilizer on soil physicochemical properties and barley yield. A factorial experiment was conducted during the 2023/2024 main cropping season using a Randomized Complete Block Design with three replications. Treatments comprised four VC rates (0, 1.25, 2.5, and 3.75&#xa0;t&#x202f;ha-1) and four NPSB rates (0, 50, 100, and 150&#xa0;kg ha-1). Soil samples were analyzed before planting and after harvest for pH, organic carbon (OC), total nitrogen (TN), available phosphorus (Av.&#x202f;P), sulfur (Av.&#x202f;S), boron (Av.&#x202f;B), cation exchange capacity (CEC), bulk density (BD), and texture. Barley yield and yield components were recorded, and partial budget analysis was performed. The initial soil was strongly acidic (pH&#x202f;5.24) with low OC (1.23%) and very low Av.&#x202f;P (6.39&#xa0;ppm). Integrated VC and NPSB application significantly (p&#x2009;<&#x2009;0.05) improved all soil properties compared to the control. The combination of 3.75&#xa0;t ha-1 VC with 100&#xa0;kg ha-1 NPSB produced the highest OC (1.53%), TN (0.25%), Av.&#x202f;P (10.30&#xa0;ppm), CEC (33.31&#x202f;cm (&#x2009;+)&#x202f;kg-1), and grain yield (5.78&#xa0;t ha-1), while reducing BD to 1.25&#xa0;g cm-3. This treatment also yielded the highest net benefit (218,335.5&#x202f;ETB&#x202f;ha-1) with a marginal rate of return of 681.75%.&#xa0;We conclude that integrated application of 3.75&#x202f;t&#x202f;ha-1 VC and 100&#xa0;kg ha-1 NPSB is a sustainable, economically viable strategy to restore soil fertility and enhance barley productivity in the acidic Nitisols of Western Ethiopia. Long-term studies are recommended to evaluate residual effects across multiple cropping seasons.