Effects of forage plantation on soil quality in the subhumid Ethiopian Highlands: implications for sustainable agriculture

This study investigated the effectiveness of four forage species on maintaining and improving soil quality and their effect on the major soil physical and chemical properties and overall soil quality change. Our study revealed that forage plantation improved the most assessed soil quality attributes compared to the conventional croplands and the initial state. Accordingly, total soil nitrogen, pH, available water capacity, soil organic carbon stock, sand, silt, and bulk density could be more effective and consistent indicators of changes in soil quality induced by the conversion of croplands to forage plantation. Based on the selected soil quality indicators, deterioration in soil quality was observed for the conventional farming system and soil quality improvement due to forage plantation. With the addition of phosphorus fertilizer and lime to control soil acidity, planting forage crops could be an alternative mechanism to control soil quality degradation and improve soil quality in acidic soils. Understanding the specific roles of different forage species in soil improvement can guide sustainable land management practices in Ethiopia and contribute to global efforts in conserving soil and water resources. The result of this study proves that forages can be effective tools in agricultural water management in the landscape. Their impact on soil physical and chemical properties, as well as overall soil quality, underscores their significance in sustainable land and water management practices. To harness these benefits, it is essential to select appropriate forage species, employ proper management techniques, and integrate forage systems into broader agro-ecological strategies.