Soils of Jelo Micro-catchment in the chercher highlands of Eastern Ethiopia: i morphological and physicochemical properties.

The Chercher highlands form one of the most intensively cultivated areas of the Ethiopian highlands. They contain numerous micro-watershed with diverse environments requiring not only spatially fitted but also temporally appropriate management methods. This requires detail information on the spatial and temporal characteristics of the resources in the existing watersheds. Small-scale resource surveys carried out in the study area before the present study could not provide detail information on the micro-level variability of the soils. In overcoming this shortcoming, a detailed soil survey was conducted in the Jelo micro-catchment situated in the northern Chercher highlands. Atributed to the great spatial variability of the soil resources, this study concentrates only on the western aspect of the Jelo micro-catchment. The major soils identified in the study area were Lithic Leptosols, Pachic Phaeozems, Endoeutric-mollic Cambisols, vertic-chromic cambisols, orthicalcic Vertisols, hypereutric Vertisols and humic-hypereutric Fluvisols. The variability of these soils and their morphological, physical and chemical characteristics wee related to geomorphic features and land-use scenarios. Soils with high contents of organic matter, nitrogen and phosphorus levels and well structured soils occupied the higher altitude uncultivated lands, whereas these characteristics were found to be of low quality in the cultivated soils. Cultivation appeared to be the major reason for the deterioration of soil characteristics suggesting that the farming system of the study area in the present context is unsustainable. Finer and soluble materials are washed out from soils at higher elevations and deposited in soils at lower elevations. As a result, the soils at the lower elevation contain more silt and clay size particles as well as higher pH values and high content of soluble minerals. Moreover, within t he soil group, he contents of plant nutrients varied significantly indicating that not only micro-watershed management but also farm level planning should be guide by information of detailed studies on soil characteristics. Therefore, considering the Ethiopian condition detail, soil survey has much to do in increasing agricultural production. An integrated study of soil-geomorphology relationships has much to contribute to environmental management and protection in mountainous areas, such as the Chercher highlands in particular and the Ethiopian highlands at large.