An examination of the effects of adding phosphorus to the soil on nodulation and P utilization in Phaseolus vulgaris L. showed a positive response in plant weight to increasing rates of phosphorus (32P) when water tension was low in the pots.
The efficiency of the utilization of fertilizer-P was directly influenced by the water content of the soil, showing increasing P accumulation after flowering.
A highly positive interaction between P addition, water content and nodulation was observed. Nodules were shown to have a high P requirement, with phosphorus (32P) contributing to an increase in the number and size of nodules.