Competition Between Chelating Agents and Roots as Factor Affecting Absorption of Iron and Other Ions by Plant Species

Abstract

The purpose of this investigation was to study the competition for Fe between chelating agents and roots as a factor affecting the absorption of Fe and other ions by plants. The investigation was divided into 2 parts: (A) Competition between chelating agents and (B) competition between roots and chelating agents. It was found that plant species differ in their capacity to absorb iron from chelating agents. In vitro experiments demonstrated a competition between chelating agents for iron. In vivo experiments showed that roots react like chelating agents in their capacity to compete for the iron in a growth medium. As the molar concentration of chelating agent was increased to exceed that of iron, the amount of iron absorbed by the plant decreased. The competitive effect of chelating agent in a growth medium was discussed as controlling factors affecting the absorption of iron and other nutrient elements by plants.