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.
Keywords: Phaseolus vulgaris; biodegradable; calcareous soil; ethylendiaminedisuccinic acid; fertilizer.