Kinetics of Phosphorus Sorption in Selected Soils of Southeastern Nigeria

This study investigated the phosphorus sorption kinetics of soils of varying parent material and soil depth in south east Nigeria. The parent materials studied were: Coastal Plain Sand, Basalt, Shale and Sandstone and the depths were: 0 – 20cm, 20-40cm and 40-60cm. Soil samples were collected from the different parent material in three replicates and a total of thirty-six composite samples were collected. The experimental design was a 4 x 3 factorial in Randomized Complete Block Design. Both parent material and soil depth as lone factors significantly influenced the rate constant (Ki), but their interactive effect was not significant. The means Ki values occurred in the following order: Shale (5.05m-1 ) > Basalt (4.67 m-1 ) > Sandstone (3.55 m-1 ) > Coastal Plain Sand (1.08 m-1 ). The rate constant (Ki) generally increased with soil depth. Relating the rate constant (Ki) to clay mineralogy showed that the values of Ki were highest in soils derived from Shale and Basalt which also had the highest concentration of Fe and Al oxides