In the past decade urea has surpassed and nearly replaced ammonium nitrate as a fertilizer. This has brought about new questions on urea and its use.
Urea, white crystalline solid containing 46% nitrogen, is widely used in the agricultural industry as an animal feed additive and fertilizer.
Commercially, fertilizer urea can be purchased as prills or as a granulated material. In the past, it was usually produced by dropping liquid urea from a "prilling tower" while drying the product. The prills formed a smaller and softer substance than other materials commonly used in fertilizer blends. Today, though, considerable urea is manufactured as granules. Granules are larger, harder, and more resistant to moisture. As a result, granulated urea has become a more suitable material for fertilizer blends.
Advantages of Fertilizer Urea

• Urea can be applied to soil as a solid or solution or to certain crops as a foliar spray.
• Urea usage involves little or no fire or explosion hazard.
• Urea's high analysis, 46% N, helps reduce handling, storage and transportation costs over other dry N forms.
• Urea manufacture releases few pollutants to the environment.
• Urea, when properly applied, results in crop yield increases equal to other forms of nitrogen.

Nitrogen from urea can be lost to the atmosphere if fertilizer urea remains on the soil surface for extended periods of time during warm weather. The key to the most efficient use of urea is to incorporate it into the soil during a tillage operation. It may also be blended into the soil with irrigation water. A rainfall of as little as 0.25 inches is sufficient to blend urea into the soil to a depth at which ammonia losses will not occur.