Some fertilizers can improve their quality and yield after they are applied to vegetables. However, some fertilizers can increase the yield after they are applied to vegetables, but they will cause pollution to the vegetables and poison the consumers. Ammonium nitrate and other nitrate nitrogen fertilizers are generally not suitable for use in vegetables. After nitrate nitrogen fertilizer is applied to the vegetable field, the nitrate content in the vegetables will increase exponentially. Nitrate is easily reduced to nitrite in the human body. Nitrite is a highly toxic substance that is extremely harmful to the human body. Ammonium chloride, potassium chloride and other chlorinated fertilizers should not be applied to tomatoes and potatoes. After the chlorine-containing fertilizer is decomposed in the soil, the ammonium or potassium ions are absorbed by the soil or absorbed by the vegetables. When the concentration reaches a certain level, the root system of the vegetable will be toxic, and the vegetables will be seriously dead. Leaf vegetable vegetables avoid spraying foliar nitrogen fertilizer. When nitrogen fertilizer is sprayed on the leaves of vegetables, the ammonium ions are easily absorbed into leaves after contact with air, and the short growing period of leafy vegetables makes it easy to accumulate nitrate in the leaves. Therefore, avoid spraying nitrogen fertilizer on leaves of vegetable vegetables. Applying micro-fertilizer to vegetables can promote high quality and high yield of vegetables. However, the demand for microelements in vegetables is very small. Excessive application of trace elements not only causes waste, but also produces poisoning to the crops and pollutes the environment. The amount of ferrous sulfate per mu cannot exceed 3.25 kg. The consumption of manganese sulfate and manganese chloride per month cannot exceed 2.05 kg. Copper sulfate cannot exceed 2 kg per mu. The amount of borax and boric acid per mu cannot exceed 1.25 kg. China Agricultural Network Editor