Characteristics and classification of the soils of tenocha-wenchacher micro-catchment, South-west Shewa, Ethiopia.

Tencha-Weenchacher micro-catchment is located between 8o16'40" and 8o19'22" N and 38o19'40" and 38o23'31" E, south-west Shewa. It covers and area of 1908 hectares. Auger hole and visual observations, aerial photo and topomap interpretations as well as descriptions of representative pits served to characterize and classify soils of the micro-catchment. Soil samples were collected from genetic horizons of representative profiles for selected soil physical and chemical analyses. The soils were characterized and mapped as dystric-gleyic Cambisols (CMgl-dy), haplic Plinthosols (PTha), dystric Nitisols moderately slopey phase (NTdy, ms), dystric Nitisols steeply slopey phase (NTdy, ss), gleyic-dystric luvisols (LVdy-gl), dystric Leptosols (LPdy), umbric Leptosols (LPum) and gleyic Umbrisols (UMgl). Many of the characteristics of these soils varied with land-use patterns. Lower bulk density values, darker colour, granular structure and soft consistency were observed in uncultivated lands, whereas higher bulk density values, reddish-brown colour, blocky-prismatic structure and hard consistency were found in cultivated land-use patterns. The texture of surface soil ranged from loam to clayey and the subsurface horizons were clayey except in Plinthosols. Relatively high contents of organic matter and total nitrogen were also measured in uncultivated soils of umbric Leptosols (18.03% and 0.86%) and gleyic Umbrisols (19.76% and 0.81%). Relatively low contents of organic matter (1.03%) and total nitrogen (0.08%) were observed in haplic Plinthosols. Percentage base saturation, soil pH, exchangeable cations and available P were generally low throughout the soil types. These indicate presence of significant leaching processes that influences fertility status of the soils. Therefore, considering soil characteristics in the management of fertility and other aspects of the qualities of the soils in the study area would be crucial.