Use of a root bioassay method to determine phosphorous availability and uptake for some crop species

Abstract

A 32P root uptake bioassay method was applied both to sand culture and soil culture grown seedlings to test the potential value of this method for determining the P availability and uptake for some selected crop species. The phosphorus uptake from the bioassay test solution w'as largely governed by the availability of P in the rooting media and P status of plants. The inverse relationship between P uptake during the bioassay and soil P status means that the method is particularly suited to natural situations with low P conditions. The results of the bioassay appear to provide integrated assessments of the demand for P and the P supply in the rooting environment. The method may be useful to diagnose deficiency of P in tree crops where remedial methods can alleviate the deficiency and increase the yield.