UAN solution is a liquid fertilizer product that combines urea, nitric acid and ammonia to form a solution containing 32% nitrogen.
UAN can be applied more uniformly than non-liquid forms of fertilizer and it can be mixed with herbicides, pesticides or other nutrients. This enables farmers to reduce costs when making several separate applications by combining these products into a single application.
Urea is synthesized commercially from two raw materials, ammonia and carbon dioxide. Ammonia is produced by reacting coal or hydrocarbons such as natural gas and petroleum derived raw materials with air (see Haber-Bosch process). This produces enough carbon dioxide to allow for direct synthesis of urea from these raw materials. Urea has a number of advantages over other nitrogen fertilizers; it is safer to ship and handle, it is less corrosive to equipment, it has a higher analysis than any other dry nitrogen fertilizer, and it can be used on virtually all crops. The high analysis means a reduced transportation and application cost per pound of nitrogen.