Impact of land use types and soil depths on selected soil physicochemical properties in Fasha District, Konso Zone, Southern Ethiopia

Agricultural activities such as deforestation, continuous cultivation and intensive grazing cause deterioration of soil properties. This study was conducted with the objective to investigate the influence of land use types (cultivated, grazing and forest lands) and soil depths (0-15 and 15-30 cm) on soil properties. Eighteen composite soil samples were collected and analyzed using standard procedures and the data was subjected to statistical analysis software (SAS). The result showed the highest mean values of pH, OC, TN, C:N, AP, CEC and exchangeable bases (Ca, Mg, K and Na) under forest and grassland soils while the lowest values of these parameters were observed in cultivated soil. Clay content and bulk density of cultivated soil were significantly (P < 0.05) higher than uncultivated lands. The result also showed the significant (P < 0.05) decline of sand fractions, OC, TN, C:N and AP with soil depth while clay content, bulk density, and exchange bases (Ca, Mg, K and Na) significantly (P < 0.05) increased with soil depth. In general, the soil properties under the cultivated land are deteriorating compared to the soils under forest and grass lands. Therefore, to improve soil properties of cultivated soil, integrated implementation of conservative tillage, crop rotation, application of manures and residue addition to the land was suggested for the study area.