Assessment of potential soil degradation on various land uses in Keduang Watershed

Abstract

Keduang watershed is a catchment area in the Wonogiri and Karanganyar districts, contributing 38.33% of sedimentation to the Gajah Mungkur Reservoir. High value population pressure is present on agricultural land in the Keduang watershed, triggering increasingly serious land degradation. Degradation in the upstream sub-watershed has a strong effect on the downstream areas. Impacts of land degradation include a decrease in land productivity and farmers’ income, as well as the occurrence of critical land. Assessment of the potential soil degradation is important as an early indicator to determine the distribution of areas that have potential soil degradation for physical, chemical, and biological soil. This research was conducted in the Keduang watershed with the land use type consisting of paddy field, wood, moor, and plantation that overlayed through land use, rainfall, slope, and soil type map. The method used in this research is guided qualification. The result showed that the Keduang watershed has a soil degradation class from low to high. The medium class dominated the potential for soil degradation in Keduang watershed with the highest potential for degradation refers to moor with a slope of >40%, rainfall of 1908 mm/year, and Inceptisols soil type.