Urea, also known as urea and carbaamide, with the chemical formula CH4N2O or CO(NH2)2, is a white crystal, tasteless and odorless, soluble in water, ethanol and benzene, slightly soluble in ether and chloroform. Urea is one of the simplest organic compounds, the main nitrogen-containing end product of protein metabolism and decomposition in mammals and some fish, and can be used as fertilizers, animal feed, explosives, glue stabilizers and chemical raw materials. Because it contains this substance in human urine, it is named urea. As a neutral fertilizer, urea is suitable for a wide range of soils and plants. It is easy to preserve, easy to use, has little damage to the soil, and is a chemical nitrogen fertilizer with a large amount of use. Urea has a nitrogen content of 46%, which is the highest nitrogen content among solid nitrogen fertilizers. Ammonia and carbon dioxide are used in industry to synthesize urea under certain conditions.
According to the Notice of the National Development and Reform Commission on the Implementation of Preferential Railway Tariff Policies for Agricultural Fertilizers and Other Slow-release Fertilizers (Fagai Price [2021] No. 1285) [1], urea has been included in the "Catalogue of Agricultural Fertilizer Varieties Implementing Preferential Railway Tariffs", and railway freight concessions have been implemented.
