Effect of Complexing Agents and Acids on the Diffusion of Zinc to a Simulated Root1
- S. M. Elgawhary,
- W. L. Lindsay and
- W. D. Kemper2
Porous ceramic tubes were embedded in soil tagged with 65Zn. Solutions were slowly passed through the tubes, allowing diffusion of the solutes into the soil and diffusion of Zn from the soil to the tubes. Solution from the tubes was analyzed for 65Zn. The solutes used were EDTA (ethylenediaminetetraacteic acid), HCl, citric acid, an amino acid mixture, and glucose. EDTA caused the greatest increase of Zn transport into the ceramic tubes (simulated roots). For example, when 10-3M EDTA was passed through such a tube Zn diffusion increased 17-fold over that occurring with water alone. The effectiveness of other agents decreased in the order listed above. Increasing the concentrations of solute generally increased 65Zn diffusion. This study demonstrates how complexing agents or acids from root exudates or from decomposing organic residues in soils may increase the transport and availability of insoluble nutrients.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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