A sorption study was conducted on soils of Edo State of Nigeria to work out phosphorus fertilizer required for raising the soil test value or P status. Eleven surface soil samples (0-15cm) differing in soli physico-chemical properties were used for study. Composite surface soil collected from each site was, treated with ten levels of P and incubated for forty two-day period. Analysis for P using Bray PI, showed that the quantity of applied P (kg/ha) required to raise the soil test value by a unit amount (mg/L), i.e. the P fertilizer factor varied from 1.28 to 2.50 with a mean of 1.76. The level of P sorption was influenced by free Fe2O3.
