(1) Promote rooting and tillering. Rooting and tillering of rice are the results of cell division and differentiation, so the differentiation of rice root primordia and the formation and differentiation of tillers are closely related to the synthesis and replication of deoxyribonucleic acid (DNA). Both DNA and RNA contain high phosphorus, generally above 10%. When cells divide, enough phosphorus is beneficial to DNA replication. RNA is a necessary condition for protein synthesis, because under the action of ATP and enzymes, various amino acids in rice first form active amino acids, and then all kinds of active amino acids are transferred to information ribonucleic acid (mRNA) outside ribosomes through transfer RNA(tRNA), and then form peptide bonds through complementary binding, and finally form protein. The normal supply of phosphorus ensures the replication and formation of RNA in rice and promotes the synthesis of protein. So that rice can take root and tiller normally.

(2) Promoting reproductive growth is beneficial to yield formation. The promotion of phosphorus on rice reproductive growth is mainly reflected in the following aspects: First, sufficient phosphorus can increase the number of spikelet differentiation. According to the previous research of Zhejiang Agricultural University, supplying RNA at the young panicle differentiation stage of rice can accelerate the spikelet differentiation and increase the number of spikelets, thus increasing the number of grains per panicle; Second, adequate phosphorus can promote the formation of sucrose and carbohydrate metabolism in the body. Under the condition of phosphorus supply, chloroplasts undergo photosynthesis to form triose phosphate. The phosphate converter on chloroplast membrane transports Pi into the membrane and triose phosphate out of the membrane, which is beneficial to the formation of sucrose. When sucrose is formed, Pi is removed to form Pi bank, and triose phosphate is continuously transported out, so that sucrose can be continuously formed in cytoplasm. Phosphorus plays an important role in carbohydrate metabolism, because hexose must be converted into hexose phosphate to be used. When breathing, aerobic respiration per gram of glucose can produce 38 ATP, while in photosynthesis, ATP is formed through photosynthetic phosphorylation. Phosphorus is an indispensable nutrient for these energy metabolism. Third, sufficient phosphorus can improve the seed setting rate and quality. According to the research, the application of phosphate fertilizer in the young panicle differentiation stage or meiosis stage can improve the seed setting rate and rice quality, because phosphorus can promote the transport of sugar, facilitate the formation of starch, accelerate grain filling and seed setting, and mature early; Moreover, the green rice rate is low, and the 1000-grain weight and seed setting rate are high. However, it is not suitable to apply phosphate fertilizer after flowering, otherwise it will affect grain filling and starch synthesis.