Urea, also known as urea and carboxamide, has the chemical formula CH4N2O or CO(NH2)2 [8]. It is an organic compound composed of carbon, nitrogen, oxygen and hydrogen, and is a white crystal. One of the simplest organic compounds is the main nitrogen-containing end product of protein metabolism in mammals and some fish.
As a neutral fertilizer, urea is suitable for all kinds of soil and plants. It is easy to preserve, convenient to use, and has little damage to soil. It is a chemical nitrogen fertilizer with a large amount of use and the highest nitrogen content. In industry, ammonia and carbon dioxide are used to synthesize urea under certain conditions.