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

Absorption of iron by plants can be increased by adding a chelating azent to a soil (2, 7, 24). Jacobson (9) found that 5 or 10 ppm of iron supplied as FeEDTA in solution cultures provided adequate iron to the plant at high pH. Other workers (7, 11, 12, 19, 20, 23, 24, 25) have confirmed these observations. Plant responses to chelate applications have been shown to differ between plant species (2) and the effectiveness of chelating agents on specific soils are known to differ (2, 24). There has been some indication (4) that roots and chelating agent compete for the Fe in a growth medium. Plant roots from some plant species are more effective competitors than others. The purpose of this investigation was to study the competition for iron between chelating agents and roots as a factor affecting the absorption of iron and other ions by plants. The investigation was divided into two parts: A. Competition between chelating agents and B: Competition between roots and chelating agents.