Asian Journal of Plant and Soil Sciences

The purpose of the study was to evaluate the effect of selected soil physical and chemical properties on phosphate (P) availability in Hadejia-Nguru floodplains using correlation matrix. Three different floodplains were strategically selected. Disturbed soil samples were collected at three different sampling points on each floodplain and at three different soil depths 0-35, 35-70, 70-105 cm. Soil parameters were determined using standard laboratory procedures; Particle size distribution using hydrometer method, soil organic carbon using Walkley-Black Method, Electrical conductivity using conductivity meter, effective cation exchange capacity (ECEC) by summation method. Soil solution pH using glass electrode pH meter, available phosphorus using Bray 1 extraction method. The soil clay content of the research area range between 10 to 28 % clay. The soil organic carbon ranged between 1.5 to 7.7 gkg^-1. The soil EA values ranged between 0.9 to 1.3 cmol(+)kg^-1. The Ca²⁺ content range between 1.11 to 8.20 cmol(+)kg^-1. The exchangeable magnesium was between low to moderate (0.22 to 0.43 cmol(+)kg^-1). The values of the exchangeable potassium in the floodplains were generally very low 0.010 to 0.026 cmol(+)kg^-1. The exchangeable sodium concentration ranged between 0.87 to 1.24 cmol(+)kg^-1. There was a significant positive correlation between soil available P and OC content (r = 0.542* P < .05), also between soil available P and pH (r = 0.525* P = .05), supported by a significant negative correlation between E.A and available P (r = - 0.604* P = .05). The soils manifest high significant negative correlation between soil available P and Ca²⁺ (r = - 0.630** P < 0.01) as well as ECEC (r = - 0.586** P < 0.01). Thus, Soil solution pH, exchangeable acidity (H⁺+Al³⁺), calcium ions Ca²⁺ and ECEC were the major soil properties that controls P availability in Hadejia-Nguru floodplains.