Compound fertilizer refers to chemical fertilizers containing two or more nutrients. The compound fertilizer has the advantages of high nutrient content, less auxiliary components and good physical properties. It is very important for balanced fertilization, improving fertilizer utilization rate and promoting high yield and stable yield of crops. The role. However, it also has some shortcomings, such as its nutrient ratio is always fixed, and the types, quantities and proportions of nutrients required for different soils and different crops are diverse. Therefore, it is best to conduct soil testing before use to understand the texture and nutritional status of the soil in the field, and also pay attention to the application with unit fertilizer to get better results. nutrient The total nutrient content of the compound fertilizer is generally high, and there are many nutrient elements. The compound fertilizer is applied at one time, and at least two main nutrients of the crop can be supplied at the same time.