Considerations on the shuttle mechanism of FeEDDHA chelates at the soil-root interface in case of Fe deficiency

• Published in: Plant and soil Vol. 379; no. 1-2; pp. 373 - 387
• Main Authors: Schenkeveld, Walter D. C, Reichwein, Arjen M, Temminghoff, Erwin J. M, van Riemsdijk, Willem H
• Format: Journal Article
• Language: English
• Published: Cham Springer-Verlag 01.06.2014; Springer; Springer International Publishing; Springer Nature B.V
• Subjects: Acid soils; Agricultural research; Agricultural soils; Agronomy. Soil science and plant productions; aluminum; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Calcareous soils; Cations; Chelates; Chelating agents; copper; Ecology; Environmental aspects; Fertilizers; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Health aspects; Iron; Life Sciences; Ligands; manganese; mechanism of action; Plant Physiology; Plant Sciences; Plant-soil relationships; Plants; Regular Article; Roots (Botany); Soil interactions; Soil mechanics; Soil plant interactions; Soil Science & Conservation; Soil sciences; Soil solution; soil treatment; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Netherlands; CuEDDHA; Shuttle mechanism; Iron chelates; EDDHA isomers; FeEDDHA; Iron chlorosis; Root; Iron compound; Deficiency; Alkylamine; Organic ligand; Iron; Mechanism; Iron complex; Vegetative apparatus; Chelating agent; Chelation; Soil plant relation; Interface; Organic compounds
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-014-2057-1

AIM: A mechanism of action for the performance of Fe chelates as soil-applied fertilizer has been hypothesized by Lindsay and Schwab (J Plant Nutr 5:821–840, 1982), in which the ligand participates in a cyclic process of delivering Fe at the root surface and mobilizing Fe from the soil. This “shuttle mechanism” seems appealing in view of fertilizer efficiency, but little is known about its performance. The chelate FeEDDHA is a commonly used Fe fertilizer on calcareous soils. METHODS: In this study, the performance of the shuttle mechanism has been examined for FeEDDHA chelates in soil interaction and pot trial experiments. RESULTS: The specificity of EDDHA ligands for chelating Fe from soils of low Fe availability is limited. Experimental support for a shuttle mechanism in soil-plant systems with FeEDDHA was found: specific metal mobilization only occurred upon FeEDDHA-facilitated Fe uptake. The mobilized metals originated at least in part from the root surface instead of the soil. CONCLUSION: The results from this study support the existence of a shuttle mechanism with FeEDDHA in soil application. If the efficiency of the shuttle mechanism is however largely controlled by metal availability in the bulk soil, it is heavily compromised by complexation of competing cations: Al, Mn and particularly Cu.