Assessing soil quality of Abargay Rangeland in Farta District, Amhara Regional State, Ethiopia

Abstract

Rangelands provide many supporting, regulative and provisioning ecosystem services to man. The mounting anthropogenic pressure on them is, however, causing their degradation and decline in productivity. Assessment of their soil quality is important for identifying sustainable land management practices. The present investigation was, therefore, carried out to assess the soil quality of adjoining protected and unprotected units of Abargay rangeland, Farta District. Cluster sampling technique was used to draw soil samples for analyses of different soil quality indicators. The protected rangeland for the last thirty years indicated significantly higher clay and silt fractions, lower bulk density, higher total porosity, higher organic matter and nutrient (nitrogen, phosphorus and potassium) contents, compared to unprotected land. The composite soil quality index, based on scoring of soil quality parameters, viz., bulk density, pH, organic matter, total nitrogen, available phosphorus and available potassium was significantly higher for protected rangeland (0.61) compared to unprotected land (0.45). Accordingly, the quality of protected rangeland was rated as fair, while that of unprotected land as poor. The soil quality of surface layer was relatively better than subsurface layer. The unprotected rangeland had negative impact on different soil quality parameters and required to be put to enclosure to warrant invaluable ecosystem services. The single value soil quality index may be used for assessment and mapping of soil quality of rangelands in Farta, Amhara region.