The content of common ferrous sulfate is 19 ~ 20%, and the content of sulfur is 11.5%. It is often used in acidophilic plants to prevent the occurrence of chlorosis. Because iron is an essential element for the formation of plant chlorophyll, the formation of chlorophyll is blocked under the condition of iron deficiency, leading to plant chlorosis and yellowing of leaves. The solution of ferrous sulfate can directly provide the iron absorbed by plants and reduce the alkalinity of soil. In addition, ferrous sulfate can also be used as an insecticide to control wheat smut, apple, pear rot and fruit tree rot, as well as for weeding, weeding and weeding.

1、 How to use ferrous sulfate:

1. The iron deficiency of fruit trees can be sprayed with 0.2% ~ 0.1% ferrous sulfate solution after leaf bud germination, once every 10 days or so, for 2 ~ 3 times until the fruit leaves turn green, but the effect of spraying after fruit leaves aging is poor.

2. The iron deficiency of gramineous crops (such as rice, wheat, sorghum) can be sprayed with 3% ~ 4% ferrous sulfate. Generally, the symptoms of chlorosis can be sprayed once at the seedling stage. If the chlorosis is serious, it can be sprayed 2 ~ 3 times continuously with an interval of 10 ~ 15 days. Ferrous sulfate solution should be prepared and used now. A small amount of wetting agent can be added during spraying to increase the adhesion of the solution on the leaf surface and improve the spraying effect.

3. If vegetables are short of iron, 0.2% ~ 0.5% ferrous sulfate can be used for spraying. When spraying, appropriate amount of water should be sprayed to avoid leaf burning. If the concentration of ferrous sulfate is more than 0.5%, it is easy to cause pesticide damage.

4. Ferrous sulfate injection method: 0.3% ~ 1% ferrous sulfate solution can be quickly injected into the tree trunk with syringe, and then the infusion bottle can be hung on the tree to let the tree absorb slowly. This method has quick effect, and can take effect if it can't be wiped off for 3 days.

5. Ferrous sulfate based application method: spray 2-2.5 kg ferrous sulfate on 50-100 kg organic fertilizer for each mature tree, after fully mixing, dig 8-10 small holes along the periphery of the tree crown, apply the organic fertilizer mixed with ferrous sulfate, and then cover the soil; for example, wheat can be directly applied to the soil, with the application rate of 30 kg per mu. The application of ferrous sulfate by basic application method can effectively supplement the iron content in soil, prevent diseases and insect pests, loosen soil, prevent soil hardening, and promote the development of crop roots. Moreover, the mixed application of ferrous sulfate and organic fertilizer can reduce the fixation of iron in soil and improve fertilizer efficiency.

2、 Precautions for ferrous sulfate application:

1. Ferrous sulfate can be mixed with medium and acid pesticides, and 0.1% neutral washing powder can be added when spraying, which can improve the effect.

2. Do not spray ferrous sulfate directly on fruit trees and vegetables at the seedling stage.

3. When spraying ferrous sulfate, it should avoid the hot sun and high temperature weather, and it is suitable to spray in the morning or after 4 p.m.