In hydroponic soilless cultivation systems, crops completely rely on nutrient solutions to obtain mineral nutrition. Iron is one of the most prone micronutrient deficiencies, and EDTA chelated iron is currently the most widely used standard iron source in hydroponic production.

Traditional ferrous sulfate is extremely unstable in hydroponic nutrient solution. A slight increase in pH will form iron hydroxide precipitate, which not only cannot be absorbed by crops, but also blocks drip irrigation pipes and adheres to the root surface causing root rot, with extremely low actual utilization rate. EDTA chelated iron exists in the nutrient solution in a stable chelated state, and hardly precipitates in the conventional hydroponic pH range of 5.5-6.5, always maintaining an active state that can be directly absorbed by roots.

EDTA chelated iron has excellent water solubility, fast dissolution speed and no residue, adapting to various hydroponic modes such as NFT, DFT and substrate cultivation. The general addition concentration is 2-5mg of iron per liter of nutrient solution. Leaf vegetables can take the lower limit, while solanaceous fruits and fruit tree seedlings can take the medium to high limit. In daily management, it is necessary to regularly monitor the pH of the nutrient solution. If the pH exceeds 7.0, it should be adjusted down with dilute nitric acid in time to avoid the dissociation and failure of the chelate structure.

In addition, EDTA iron can stably coexist with macronutrients and other micronutrients in the nutrient solution without antagonistic reaction. It is the core standard component of formula nutrient solutions, which can continuously ensure crop chlorophyll synthesis, avoid young leaf chlorosis and maintain normal crop growth rate.