Characterization, Classification and Suitability Evaluation of Soils in Ukum, Benue State, Nigeria for Maize and Yam Production

Soil characterization, classification and evaluation provide useful information for the understanding of soil, its potentials and limitations for crop production. The study was to determine the morphological, physical and chemical properties of the soils; classify the soils; and evaluate their suitability for maize, cassava and yam production. Three land utilization types (maize, cassava and yam) with a control plot each were used for the study. One soil profile pit was dug in each land utilization type and control. The pedons were described in-situ following the procedures in FAO, s guidelines for soil profile description. A total of 23 samples were collected from the diagnostic soil horizons. The soils were classified using USDA Soil taxonomy and correlated with FAO/UNESCO World Resource Base. The suitability of the soils for maize, cassava and yam production was assessed using the non parametric and parametric methods of land evaluation. Morphologically, the soils were well drained and very deep with predominantly brownish gray (5YR5/1) and dark gray (2.5Y 5/2). The soil structures varied from weak fine granular structure to weak/moderately medium angular and sub-angular blocky structures. Soil texture varied from sand to sandy loam. The soil bulk density and total porosity varied from 1.42 to 1.72 g cm-1 and 36.98 to 46.42 %, respectively. The pH of the soils varied from slightly acidic to moderately acidic. Organic matter and total nitrogen in the soils were rated very low to low. The soils were classified at various great group levels of ultisols. The soils were moderately suitable.