Urea, also known as urea or carbonamide, has a chemical formula of CH4N2O or CO(NH2)2. It is a white crystal, tasteless and odorless, easily soluble in water, ethanol and benzene, and slightly soluble in ether and chloroform. Urea is one of the simplest organic compounds and the main nitrogen-containing end product of protein metabolism and decomposition in mammals and some fish. It can be used as fertilizer, animal feed, explosives, glue stabilizer and chemical raw material. Because this substance is contained in human urine, it is named urea. As a neutral fertilizer, urea is suitable for all kinds of soils and plants. It is easy to store, easy to use, and has little destructive effect on the soil. It is a chemical nitrogen fertilizer with a large usage. Urea contains 46% nitrogen (N), which is the highest nitrogen content among solid nitrogen fertilizers. In industry, ammonia and carbon dioxide are used to synthesize urea under certain conditions.