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
vulgariscv. 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.