There are many types of compound fertilizers. According to the form of nutrient elements, they can be divided into potassium sulfate type compound fertilizers, potassium chloride type compound fertilizers, ammonium nitrate nitrogen type compound fertilizers, etc.; according to the manufacturing method, they can be divided into chemical compound fertilizers and mixed compound fertilizers. Large categories; according to the nutrient content, it can be divided into high, medium and low concentration series of compound fertilizers, all of which have the effect of promoting high and stable crop yields.