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.
