The chemical formula of ferrous sulfate is FeSO4 · 7H2O, anhydrous ferrous sulfate is white powder, containing crystal water is light green crystal, commonly known as "green Gong". Ferrous sulfate has a wide range of uses. For example, ferrous sulfate can be used as fertilizer and herbicide in agriculture, improve soil acidity, supplement iron for acid plants, alleviate yellow leaf disease of flowers, trees and fruit trees, and can also be used with watering and fertilization. Agricultural ferrous sulfate can be used as an insecticide to control diseases of wheat and fruit trees, and also as a fertilizer. It is a catalyst for plants to produce green pigment and plays an important role in plant absorption.

1. Ferrous sulfate can be used as a fruit and vegetable herbicide to improve soil pH (especially in saline alkali soil) and inhibit the growth of weeds in the field.

2. Ferrous sulfate can prevent diseases and insect pests, especially scab of apple and pear, rot of fruit trees, and rot of fruit bark. It can also be used as fertilizer to remove moss and lichen from tree trunks.

3. It can be used as a pesticide to control wheat head smut.

4. The application of ferrous sulfate fertilizer can also promote the photosynthesis of flower leaves to synthesize chlorophyll, and the crops look more green and plump.

Among these factors, agricultural ferrous sulfate has a good therapeutic effect on "green deficiency disease" of crops, which can make the hardened soil loose and powerful, promote the development of plant roots, accelerate the synthesis of various substances, enhance the disease resistance of crops, and promote the activity of enzymes.