Correlation of soil phosphorus analyses with response of tropical pastures to superphosphate on some north Queensland soils

Abstract

From the results of twenty-one field experiments dealing with the establishment of tropical pastures, correlations between per cent yield and soil phosphorus analyses showed significant relationships for the Kerr- von Stieglitz and Colwell methods but not for the Bray P2 method. To separate responsive and non responsive soils critical values of 17.5 p.p.m. P for the Kerr-von Stieglitz and 20 p.p.m. for Colwell methods are proposed. Correlations with the main Chang and Jackson soil phosphorus fractions are reported and discussed.