Evaluation of anion exchange membranes to estimate bioavailable phosphorus in native grasslands of semi-arid northwestern Australia

Abstract

Anion exchange membranes (AEMs) were used to assess the P status of semiarid sub-tropical soils of high P sorption capacity from the Pilbara region in northwestern Australia. We determined the most appropriate procedure for using AEMs in these soils using a factorial of extraction ratios and shaking times and compared the method with extraction by water. Significantly more inorganic P (Pi) was extracted by the membranes (AEM-Pi) than by water, and the amount extracted increased with extraction time but was generally independent of the extraction ratio. Maximum AEM-Pi was 3.61 μg g-1 after eight hour extraction. The AEM procedure was compared with traditional extraction procedures using 0.5 M..