Effects of agroforestry land use on soil physicochemical properties and soil quality in Gilgel Gibe I catchment, Southwestern Ethiopia

Agroforestry plays a vital role in restoring degraded soil and delivering essential ecosystem services; making it an effective land use management strategy. However, in the study area, its influence on soil properties enhancement has received little attention. The aim of this study was to examine the effects of Agroforestry land use (ALU) practices on selected soil physicochemical properties and soil quality (SQ). Three ALU practices: home garden (HG), coffee-based agroforestry (CBA), and parkland (PL) were purposefully selected in the Nadi and Yedi micro watersheds. A total of 54 composite and 54 undisturbed soil samples were collected from soil depths (0-20, 20-40, and 40-60 cm) per agroforestry land use and examined for soil physicochemical properties. The findings revealed that soil chemical properties such as soil organic carbon, pH, total nitrogen and available potassium decreased as soil depth increased from 0-20 to 40-60 cm. Porosity, bulk density, sand content, soil organic carbon, pH, and plant available water content significantly (p < 0.05) vary among ALU practices. Soil organic carbon, bulk density, available phosphorus, clay content, and pH were identified as soil quality indicators in a minimal data set through principal components analysis. The soil quality index (SQI) mean value was highest under HG, followed by CBA and PL in both micro watersheds. Consequently, high soil quality was verified under HG and CBA compared to PL in both micro watersheds. The SQI mean value decreased as soil depth increased. Thus, parkland use resulted in more significant physicochemical property and soil quality degradation compared to other practices. Therefore, we recommend a regenerative and sustainable land use practice that restores soil health, biodiversity, ecosystems services, and enhances community participation in this era of climate change.