Impacts of Land Use Types on Selected Soil Physico-Chemical Properties of Loma Woreda, Dawuro Zone, Southern Ethiopia

Abstract

A study was conducted in Loma Woreda, Dawuro Zone, Southern Ethiopia, to investigate the impacts of land use types (forest, grazing and cultivated) on the selected soil physico chemical properties of the study area. Composite surface (0-20 cm) soil samples were collected randomly from three sites of each land use which were adjacent to each other and subjected to laboratory analysis. The results of the study revealed that there was relative variation in proportion of sand and clay content among the land use types though they have the same textural class. The bulk density of the soils decreased from grazing to cultivated and then to forest land, while total porosity decreased from forest to cultivated and then to grazing lands. The average soil pH-H2O value of the area varied from very strongly acidic to strongly acidic. Exchangeable acidity and Percent Acid Saturation were significantly lower by about 60.02 and 61.54% in the forest soils than the soils of cultivated lands, and 29.70 and 38.32% than that of grazing lands, respectively. As compared to the soils of forest land, the amount of soil OM, TN and CEC in cultivated land have declined by about 76.53, 60.83 and 38.97%, respectively. The available P, exchangeable bases and PBS have shown decreasing trends in the soils of forest to grazing and then to cultivated land uses. From this study, it can be concluded that the soil fertility and quality were well maintained relatively under the forest land, while the impact on most parameters were negative on the soils of the cultivated land. Applications of lime, organic and inorganic fertilizers and crop rotation especially in the cultivated lands may enhance the productivity of the soils, implying the need for undertaking integrated soil fertility management in sustainable way to improve and maintain the favorable soil properties.