The main physiological functions of phosphorus (P) PO43-, HPO42- and H2PO4- constitute important compounds such as nucleic acid, nucleoprotein, enzyme and ATP. Promote sugar metabolism, nitrogen metabolism and fat metabolism; Promote plant growth, tillering, root elongation and flowering and fruiting; Enhance the stress resistance of plants such as drought resistance, cold resistance, saline-alkali resistance and pest resistance. As an activator of various enzymes, potassium (K)K+ participates in and regulates various metabolism. Promote photosynthesis and transportation and transformation of photosynthetic products; Adjust the absorption and reduction of nitrate and the synthesis of protein; Promote crop water conservation; Enhance the stress resistance of plants such as drought resistance, cold resistance, saline-alkali resistance and pest resistance. Calcium (Ca)Ca2+ is a component of cell wall, which contributes to the stability of cell membrane. Promote the formation of new cells and the growth of roots by affecting cell division; As an activator of various enzymes, it regulates various metabolism in the body; Adjust the physiological balance of the medium. Magnesium (Mg)Mg2+ the constituent elements of chlorophyll; As an activator of various enzymes, it enhances carbon metabolism, nitrogen metabolism, phosphorus metabolism and fat metabolism; Promote vitamin synthesis and coordinate the balance between ions. Sulfur SO42- and SO32- constitute important compounds, such as protein, enzymes and vitamins. Promote chlorophyll formation; Participate in the redox process; Enhance the cold resistance and cold resistance of plants.