Absorption of magnesium and its influence on the uptake of phosphorus, potassium, and calcium by intact groundnut plants

Abstract

In this investigation absorption characteristics of magnesium were investigated by intact groundnut (Arachis hypogaea L.) plants from dilute nutrient solutions over an extended period of 39 days of growth. A magnesium concentration of about 120 μM was found to be the saturation concentration above which the magnesium flux was more or less constant. The maximum sensitivity to concentration change in the nutrient solution in the derivative curve for growth occurred sooner than the maximum sensitivity for the uptake. Magnesium suppressed the uptake of potassium and calcium, but the uptake of phosphorus was independent of magnesium concentration. This inhibiting effect of magnesium on the absorption of potassium and calcium may be important in the potassium and calcium nutrition of groundnut plants. re]19730426