Effects of Integrated Soil Fertility Management Practices on Soil Properties under Wheat and Faba Bean Production in Dire and Legedadi Watersheds of Ethiopia

Abstract

Purpose Soil degradation and nutrient depletion have gradually increased and become serious threats to agricultural productivity in Ethiopia. This research aims to assess the effects of selected integrated soil fertility management (ISFM) practices on soil properties in Dire and Legedadi watersheds, central highlands of Ethiopia. Knowing how ISFM practices affect soil quality indicators will enable us to take the appropriate measure to improve sustainable crop yield while reducing the ongoing soil degradation. Methods A field experiment of eight treatments under a randomized complete block design with three replications was conducted in the 2021 and 2022 cropping seasons. Selected soil physicochemical properties were determined following the standard protocols. Soil organic carbon (SOC) stock, Nitrogen (N) stock and carbon sequestration (t ha− 1) were calculated according to Donvan’s equation. Results Analysis of variance showed that soil samples collected from each plot indicated significant differences in soil organic carbon, total Nitrogen (TN), available phosphorus (Pav), exchangeable bases (Ca2+, Na+, and Kexc) and Cation exchange capacity (CEC). Soil pH and moisture showed improvement compared to the pre-planting soil sample. Combined application of vermicompost (VC), NPS + Urea fertilizers significantly (p < 0.05) increased SOC, Pav, Kexc, Na+, and CEC. The highest TN content (0.36% and 0.30%) in Dire and Legedadi sites, respectively, water holding capacity and soil carbon stock were obtained in 100% VC rate added treatment. Similarly, the wheat-faba bean intercropped plot showed a significant (p < 0.05) effect on soil carbon stock and sequestration over the control in both study sites. Conclusions Integrated application of VC and NPS + urea fertilizers improved soil quality. From results of the current experiment for two years, it can be concluded that integrated application of 50% VC with 50% NPS + urea fertilizer improved most physicochemical properties soil of Luvisol and Vertisol in Dire and Legedadi sites, respectively. This implies that the combined application of VC and NPS + urea fertilizers helps farmers to reduce the use of inorganic fertilizer requirement by 50%.