Which chemical fertilizers should not be applied to vegetables?

Ammonium nitrate and other nitrate nitrogen fertilizers are generally not suitable for use in vegetables. Nitrate-nitrogen fertilizers will multiply the nitrate content in vegetables after being applied to vegetable fields. Nitrate is easily reduced to nitrite and nitrite in the human body. It is a highly toxic substance that is extremely harmful to the human body. Ammonium chloride, potassium chloride, and other chlorinated fertilizers are not suitable for use in tomatoes. After the chlorine-containing fertilizer is decomposed in the soil, ammonium or potassium ions are absorbed by the soil or absorbed by the vegetables. When the concentration reaches a certain level, it will affect the vegetable roots. Poisoning occurs. Severe vegetables can cause death.

Leafy vegetables are not allowed to spray nitrogenous fertilizers on leaf surfaces, and nitrogen fertilizers are sprayed on the leaves of vegetables. After the ammonium ions are contacted with air, they are easily converted into nitrate ions and absorbed by leaves. In addition, the growth period of leafy vegetables is short, and nitric acid is easy to make. Salt accumulates in the leaves. Therefore, avoid spraying nitrogen fertilizers on foliar vegetables.

Applying micro-fertilizer to vegetables can promote the high quality and high yield of vegetables, but the demand for microelements from vegetables is very small. Excessive application of trace elements not only causes economical waste, but also produces poisoning to the crops and pollutes the environment. Under normal circumstances, the amount of ferrous sulfate can not exceed 3.25 kg per mu, the amount of manganese sulfate, manganese chloride per month can not exceed 2.05 kg, the amount of copper sulfate can not exceed 2 kg per mu, and the amount of borax and boric acid can not exceed 1.25 kg per mu. .