Used as a nutrient supplement in hydroponic systems and agriculture to prevent and correct iron deficiency in plants, especially in alkaline soils where iron becomes less available. Commonly applied in chelated form (e.g., Fe-EDTA or Fe-DTPA) to enhance uptake. Also utilized in water treatment processes to remove phosphates and as a catalyst in certain chemical reactions. In industrial settings, serves in the preparation of iron-containing compounds and coatings.