Phosphorus‐Iron and Phosphorus‐Zinc Relationships in Corn (Zea mays L.) Seedlings as Affected by Mineral Nutrition1

The P‐Zn and P‐Fe relationships in corn (Zea mays L.) seedlings as affected by high P levels and low and high levels of other nutrients, varied individually, were determined. With high P levels, shoot growth was increased only by high Zn, but was decreased by deficiencies of other nutrients. N and K favored P nutrition more than Fe or Zn nutrition. Ca antagonized P, Zn, and Fe, while Mg synergized P and Zn but not Fe. Similarly, Cu and Mn antagonized shoot P and Fe concentrations and had little effect on shoot Zn concentrations. The most marked interaction at high P levels was between Fe and Zn, which mutually antagonized translocation more than absorption.