Assessment of Degradation in Soils of Transplanted Shea Tree (vitellaria Paradoxa Gartn C. F.)under Two Land Use Types at Bida, Niger State

Land use affects the fertility and management of soils. The influence of contrary land use types imposed on a Shea field was studied at NIFOR Substation, Bida, Niger state. The field, a sparse grass fallow measuring a 100m X 100m was demarcated into two equal halves. A portion of it was cleared and planted to melon while the sparse grass fallow was retained in the other portion. Composite surface soil samples were collected at 0-15cm in three replicates from each land use type and analyzed for physico-chemical properties in the laboratory. Degradation was assessed using FAO and Snakin et al. indicators and criteria for physical, chemical and biological degradation of soils. The estimation of the degree of degradation was based on physical, chemical and biological parameters of land use types. Except Ca, soil chemical properties differed significantly under the land use types though land use had no effect on texture of the soils. The soils under Shea cultivation at NIFOR Substation had a score of 4 each under the two land use types and were therefore very highly degraded with respect to nitrogen. Soils under grass fallow had a score of 3 and was highly degraded with respect to phosphorus while soils under melon had a score of 1 indicating none to slight degradation with respect to phosphorus. Soils under grass fallow had a score of 3 with respect to potassium and was therefore highly degraded while soils under melon had a score of 4 and was very highly degraded with respect to potassium. Chemical and biological degradation were as a result of soil fertility depletion and organic matter decline. The use of integrated fertility management system is suggested as a possible means of improving the soils for Shea tree cultivation in the area.