ABSTRACT

A soil survey and fertility mapping of Okoko Item in Bende Local Government Area of Abia State,was carried out for efficient fertilizer use and crop production. The study was undertaken because Okoko Item is a major food producing community in the State  The farmers are facing the challenges of scarcity and high cost of fertilizers as well the increasing declining soil fertility due to population pressure on the land and poor soil management. The study area covered 1, 885.5 ha. A free survey method of soil survey was adopted. The results showed that four soil mapping units ( Okoko 1, Okoko 11, Okoko 111 and Okoko 1V) were delineated and classified. Okoko 1 (1,202 ha) occupies a non gravel to gravelly level plain. The soils are shallow to moderately deep. Okoko 11 (230.5ha) are sandy to loamy and well drained and occours on elevation 116-209m above sea level. Okoko 111 (227.2ha) occupied loamy to clayey soils on undulating topography with rock outcrops. Okoko 1V (224.9ha) are deep, well drained coarse loamy that dominated by grssland vegetation. The soils are generally acidic, ranging from strongly acid while the (pH 5.00 – 5.50) to very strongly acid (4.50 – 5.00).  Total N and exchangeable K ranged from low to medium (0.08 – 0.20 % N) and (0.06 – 0.24 cmol/ kg K) while available P ranged from medium to high (15 - 45 mg /kg P). Majority of the soils are arable  Class II (1657.4ha)  128.1ha are non arable while soils occuring within the summit (128 - 137 m above sea level) belong to Class IV land. Three land capability units: Class IIew, Class IIen and Class Ives were delineated based on the degree of limitations (soil depth, rock out-crop and boulders; wetness, soil erosion and low nutrient) to sustainable crop production. Generally, it is concluded that the soils are arable but the choice of crops will differ based on the capability units. The soils at the northern end (towards Ugwueke) are of medium fertility while the soils at the southern end (towards Igbere) are of low fertility.The soils were characterized and classified using USDA Soil Taxonomy and correlated with World Reference Base (WRB).  Four soil mapping units viz: Okoko I, Okoko II, Okoko III and Okoko IV were delineated and classified as Mollic Endoaquents (USDA); Eutric Gleysols (Humic)(WRB), Typic Rhodudults (USDA); HaplicAcrisols (Loamic)(WRB), Typic Plinthudalfs (USDA); Pisoplinthic Plinthosols (Clayic) (WRB) and Rhodic Paleudults (USDA); Haplic Acrisols (Loamic) (WRB), respectively The land capability map and soil fertility maps are recommended as visuals in extension education, as well as planning tools for agronomist, farmers and policy makers for sites selection for crop production, and as a guide for fertilizers use within Okoko Item community.