Evaluation of Soil Tests for Phosphorus and Its Relation to Inorganic P Forms in Vertisols

Available P status as estimated by different extractants and its relationship with different inorganic P forms in Vertisols located in different agro-elimatic zones of northern Karnataka is reported. The P extracting power of different extractants was in the order: Truog > Bray No.1 > Olsen > Datta and Kamath > Morgan. Olsen and Bray No. 1 extractants were consistent in extracting P from specific P fractions than the other three extractants.