[ S,S ]-EDDS Ligand as a Soil Solubilizer of Fe, Mn, Zn, and Cu to Improve Plant Nutrition in Deficient Soils.

The deficiencies of iron, manganese, zinc, and copper in calcareous soils are a worldwide problem affecting plant growth and fruit quality, usually minimized by the application of recalcitrant synthetic metal chelates. Biodegradable ligand [ S,S ]-EDDS is an eco-friendly substitute. This study investigates the capacity of [ S,S ]-EDDS to mobilize micronutrients from agronomic soils and improve plant nutrition. A batch and a plant experiment ( Phaseolus vulgaris cv . Black Pole) with three agronomic soils was conducted to monitor the micronutrients solubilized by [ S,S ]-EDDS, the ligand degradation, and plant uptake. The results demonstrated the high capacity of [ S,S ]-EDDS to solubilize Fe and other micronutrients related to its chemical behavior and the enhancement of plant nutrition. The best results were shown in sandy-clay soil with low Fe, typically found in the Mediterranean areas. The results support the direct application of the ligand to soils and a possible biotechnological application of the ligand-producer bacteria.