Determination of phosphate in soil extracts by automatic colorimetric analysis

Abstract

Abstract Automatic techniques have been developed for analysis of various soil extracts for phosphate content using Technicon “AutoAnalyzer”; equipment. Manifold arrangements for Truog, Bray and Olsen soil extracts and for phosphate fractions separated by the Chang and Jackson procedure are described. The colour development manifold based on the molybdate ‐antimony ‐ ascorbic acid method of Murphy and Riley gave a linear calibration over the range 0 ‐ 1.2μg P/ml. Automatic measurements were as accurate as manual methods.