Geographic Information System (gis) Approach in Suitability Study of Asu River Group Soils of Old Ohaozara - Southeastern Nigeria for Rice Production

This research work was carried out in Ivo Local Government Area, Old Ohaozara, Southern Ebonyi State, Southeastern Nigeria. Using Digital Elevation Model (DEM) which is a component Geographic Information System (GIS). Yearly precipitation and relative humidity scored 95% in all the investigated pedons which included Upland, Lowland, and Irrigated soils placing them in Suitability class 1 (S1) while mean temperature scored 85% in all pedons of Old Ohozara soils. The Suitability Aggregate scores and suitability classification of three Rice Soils of Ivo Local GA in Old Ohaozara indicated that the upland, lowland and irrigated pedons were all (potentially and currently) marginally suitable (S3) except upland pedons 2 and 3 that were currently not suitable- N1 using a parametric method of evaluation. Non-parametric evaluation of soils of Old Ohaozara suggests that all pedons were (potentially and currently), marginally suitable. Old Ohaozara uplands currently and potentially had limitations of wetness for pedons 1 and 2, wetness and fertility for pedon 3. Lowland and irrigated soils of the region currently and potentially had limitations of fertility and toxicity in all pedons except lowland pedon 3 with only fertility limitation. The DEM revealed that the upland terrain here graded from 45.3 – 53.7 m, the lowland region had terrain ranging from 35.0 – 45.7 m while the irrigated region ranged from 53.8 – 68.6 m above sea level in their elevations. The downslope soils dominating the lowland soils with lower terrain which are relatively plain will likely favour the rice cultivation more than the upland and irrigated zones. This is due to the economic feasibility of the lowland soils for the poor farmers which constitute a majority in the study area.