THE EFFECT OF p H ON THE UPTAKE AND ACCUMULATION OF PHOSPHATE AND SULFATE IONS BY BEAN PLANTS

Phosphate uptake above pH 6.0 followed the concentration of H2PO4. Sulfate studies were used to aid evaluation of phosphate data. Phosphate absorption was nearly linearly proportional to transpiration at pH 4.0; at pH 8.7, phosphate absorption occurred only early in the experiments. It was inferred that phosphate entered as H2PO4; that which entered at pH 8.7 did so as the result of a depressed pH at the absorption sites.