EFFECT OF PHOSPHATE FERTILIZER APPLICATION ON ZINC ADSORPTION BY SOME SOILS OF JERE LOCAL GOVERNMENT OF BORNO STATE

The present study evaluated the effect of phosphate fertilizer application on zinc adsorption by some sols of jere local government area of Borno state Composite Soil samples(0-20cm) representing the three soil textures were collected from Zabarmari, Ngudda and Khadamari. The soils were air dried, gently crushed, and passed through a 2 mm sieve prior to laboratory analysis. The soils are analysed for their physico chemical properties. Batch adsorption experiments were carried out by adding Zinc solutions of varying concentrations to the soils under phosphate- treated and untreated conditions. The soil- solution mixtures were shaken for equilibration, filtered, and the equilibrium zinc concentration in the filtrate was determined using standard laboratory procedures. The amount of zinc adsorbed by the soils was calculated as the difference between the initial and equilibrium zinc concentrations. The results showed that the soil of Zabarmari was neutral in reaction , that of Ngudda was slightly acidic. The textural class of the soils of Zabarmari , Ngudda and Khadamari were sand ,silt loam and clay, respectively. Zinc adsorption increased with increasing zinc concentration in all the soils studied. The adsorption data were analyzed using Langmuir and Freundlich adsorption isotherm models. The low coefficients of determination indicated poor conformity to the models. The study showed that a slightly higher amount of zinc was adsorbed by the soils treated with phosphate. The study concluded that phosphate fertilizer application influenced zinc adsorption and availability in soils.