CHARACTERIZATION OF SOILS AND AGRICULTURAL POTENTIAL OF GACHO BABBA DISTRICT, GAMO ZONE, SOUTHERN ETHIOPIA

Abstract

ABSTRACT Characterization and classification of the soils of a particular area is crucial for determination of its potential and limitations for sustained agricultural production and productivity. Therefore, the objectives of this study were to characterize soils, classify and determine agricultural potential of Gacho Babba District. The area lies between 050 96’ 50’’ to 060 21’ 10’’ N and 370 34’ 60’’ to 370 52’ 90’’ E at an elevation varying from 1280 to 3045 masl. Six representative pedons were opened at upper, mid and low topographic positions and both disturbed and undisturbed soil samples were collected from these pedons. Also, composite soil samples were augured from surface horizons. Soil parameters were analyzed using standard procedures and the data were subjected to analysis of variance. Mean separation was done using the list significant difference. The field as well as the laboratory data revealed that the textural classes of most of the pedons were sandy clay loam followed by clay loam. The bulk density value varied from 1.15 to 1.37g cm-3 in the surface soil. Soil pH ranged from 4.13 to 6.57 in the surface horizons. The organic carbon, total nitrogen, available phosphorus and available potassium were low to moderate, very low to moderate and low, respectively. The cation exchangeable capacity and base saturation of the soils varied from high to very high and very low to moderate respectively. The contents of exchangeable bases were in the order of Ca2+ > Mg2+ > K+ > Na+. Five soil types, Cambic Umbrisols, Hyperdystric Nitisols, Haplic Alisols, Stagnic Fluvisols and Pellic Vertisols were identified based on classification system of world reference bases for soil resource. Across toposequence soils have low, intermediate and high soil quality. The lands of studied soils were belongs marginally, moderately and highly suitable in upper, mid and low slope position respectively. Topography variation influences the soil formation, whereby the soils in the upper and mid slope positions were developed from in situ weathering parent materials whereas, deposition in lowland. To maintain nutrient and soil loss, it needs effective conservation measure.