Abstract:
In Tach Karnuary watershed higher land degradation and soil erosion problems has a deleterious impact on soil fertility due to land use types and slope grdient variation. The objective of the study was to evaluate effects of different land use types on selected soil physico-chemical properties along slope classes. The experiment was laid out in the randomized complete block design (RCBD) with two factors (land use and slope class). A total of 24 composite samples were collected from 0-20 cm depth under four land use types across two slope gradients. The undisturbed soil samples were analyzed for bulk density in an oven at 105℃; while the composite soil samples were analyzed for soil texture, pH, organic carbon (OC), CEC, exchangeable cations, total N and available P using standard procedures. For data analysis, general linear model procedure of SAS version 9.4 was used. The results showed that, most of the soil physico-chemical properties varied with land use types and slope classes. Consequently, the values of sand, silt, clay, bulk density, porosity, pH, Av. P, TN, OM, CEC, exchangeable cations (Ca+2, Mg+2, K+ and Na+) were highly significantly (p< 0.01) affected by a change in slope classes. Similarly, sand, silt, clay, bulk density, porosity, pH, Av. P, OM, TN, CEC, Ca+2, Mg+2, K+, Na+, PBS were significantly (p <0.05) affected by land use types. The mean values of clay, porosity, pH, OM, TN, CEC, Ca2+, Mg2+, K+ and Na+ were higher in the lower slope classes of natural forest compared to other land uses. In contrast, the mean values of silt and Av. P were higher in cultivated land as compared to other land use types. Generally, land use type and slope gradient cause variation in physico-chemical properties of the soil.
Key words: cultivated land, eucalyptus plantation and grazing land.