Characterization, Classification and Mapping of Soils of Agricultural Landscape in Tana Basin, Amhara National Regional State, Ethiopia

Abstract

A study was conducted at different locations of Tana sub basin to understand their physico-chemical and mineralogical properties of the soils and characterize, classify and map them. Six major soil units were identified in the area including Luvisols, Vertisols, Nitisols, Leptosols, Gelysolsl and Fluvisols on the basis of land forms and surface texture. Morphological properties of the soils reveal that Luvisols are deep, well drained and generally loamy sand in texture. Vertisols (VR) were poorly drained with deep rooting zone and texture varies from clay on the surface to heavy clay in the subsoil. Lithic Leptosols have an impermeable layer at less than 50 cm depth with generally gravelly sand texture. The texture of the soils in the study area are generally characterized by clay to heavy clay and have workability problems during rainy seasons. The dominant exchangeable bases were calcium and magnesium with the soils having high base saturation. The Vertisols have neutral to slightly alkaline reaction (pH). The soil reaction of Nitisols at Jema and Sekela sampling sites were 6.5 and 5.5, respectively. Soil reaction of Luvisols was 5.3. Available phosphorous in all soils are low to very low. Total nitrogen and organic carbon contents also are low to very low. The soils found within the Tana sub-basin were classified as Haplic/Chromic Luvisols, Haplic/Rhodic Nitisols, Lithic Leptosols, Pellic/Chromic Vertisols and Cambic Cambisols and other association soil types such as Fluvisols and Regosols.