EDTA extractable phosphorus in soils as related to available and inorganic phosphorus forms

Abstract

Twenty surface soil samples, representing two major soil orders alfisols and vertisols were extracted with 0.01N Na2 EDTA solution (pH 4.8) at a soil/solution ratio of 1:25. Phosphorus in the extract was determined following ammonium molybdate‐stannous chloride colorimetric method. The EDTA extractable P showed significant positive correlations with extractable P according to the Olsen, Morgan, Bray 1 and 2 and also with inorganic phosphorus fractions associated with Al, Ca and Fe