Assessment of three extraction methods on the concentration of available phosphorus in soils developed on three different parent materials

Application of phosphorus (P) fertilizer is commonly based on soil testing for which a variety of soil P extraction methods are in use. The aim of this study was to compare three methods of P extraction from soils that had been derived from three parent materials in terms of their extraction yield and relation to soil properties. To achieve this, soils derived from Coastal plain sand (CPS) from Obio Akpa in Oruk Anam LGA, Beach ridge sand (BRS) from Ikot Akpaden in Mkpat Enin LGA and Sandstone (SS) from Ikot Obio Ise in Ini LGA were sampled at two depths (0-15 and 15-30 cm). The soil samples were processed in the laboratory and used to conduct routine analyses. For P determination, three extractants, i.e., H2O, CaCl2 and Bray-2 were used. The extracted P varied in concentration and increased in the order H2O <CaCl2 < Bray-2 being more efficient in the extraction of P in BRS, SS and CPS. Indications from this study is that Bray-2 is a suitable extractant that could be used for P extraction in the studied soils.