Evaluation of P Fractions Contributing to Available P Extracted by Some Common Soil Test Methods

Seventy three soil samples obtained from 15 soil profiles in Kangra Valley (H.P.) were analysed for inorganic soil P fractions and available P by the methods of Bray and Kurtz (P₁), Olsen et al, and Morgan to determine the relationship between P fractions and soil test values. Ca-P fraction made nonsignificant contribution to Bray P₁ and Olsen methods, but 16% variation in Morgan P values was explained due to variations in Ca-P. The Al- and Fe-P fractions contributed significantly to Olsen P and Bray P₁, the contribution of the latter being higher. Bray P₁Y and Olsen methods resembled in their P extraction patterns from different inorganic P fractions.