Abstract

This investigation was carried out to determine the physico-chemical properties of soils under Acacia senegal and Acacia seyal stands, in Government Secondary School, Tambuwal as a case study in semi-arid zone of Nigeria. Soil samples were collected systematically in three replications at two depths of 15cm and 30cm at each sampling site under the tree canopies. Soil samples outside the tree canopies served as control. The experiment was laid in a 2×3 factorial experiment in completely randomized design (CRD). Samples were analyzed for pH, Electrical conductivity (EC), Organic carbon (OC), Nitrogen (N), Phosphorous (P) and Potassium (K). Statistical analysis was performed on the data obtained, using Duncan Multiple Range Test (DMRT) at 5% for mean separation. The result for mean pH value showed that the control sample recorded a mean pH value of 6.7 which was significantly different from the mean pH values of soil samples collected under the canopy of A. senegal (6.26) and A. seyal (6.39)  The mean values for Electrical conductivity for A. senegal (61.97S/m). A. seyal (43.47) and the control (46.00) showed no significant difference (Р≤ 0.05). The effect of depth and the interaction between the depths was observed to have no significant difference for N. It can be deduced from this present study that leguminous tree species improve the soil physical and chemical properties.