ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 70 Number 2
Evaluation of P-sorption capacity of forest and savanna soils of Nigeria
Phosphorus-sorption capacity of soils derived from four different parent materials in the forest and savanna zones of Nigeria was evaluated by shaking a fixed weight of each soil type with known concentrations of P. Quantities of added P sorbed by the Inceptisols and Ultisols of the forest zone were significantly higher than the quantities sorbed by the Entisols and Alfisols of the savanna zone. The two soil types in each group, however, exhibited essentially the same sorption capacity. In terms of the relationships between the soil characteristics, and the ability to sorb P, phosphorus-sorption capacity had positive correlations with clay content, exchangeable Al, and with oxides of Fe and Al, but had negative correlations with pH and exchangeable Ca and no correlation with CaC03 or exchangeable Mg.
Keywords: Standard phosphate requirement; P sorbed; Equilibrium P concentration; Savanna soils; Rainforest soils; Nigeria