ammonium nitrate

The chemical compound ammonium nitrate, the nitrate of ammonia with the chemical formula NH4NO3, is a white crystalline solid at room temperature and standard pressure. It is commonly used in agriculture as a high-nitrogen fertilizer, and it has also been used as an oxidizing agent in explosives, including improvised explosive devices. It is the main component of ANFO, a popular explosive. It is used in instant cold packs, as hydrating the salt is an endothermic process.
Ammonium nitrate is an important fertilizer with the NPK rating 34-0-0 (34% nitrogen).It is less concentrated than urea (45-0-0) giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrate's advantage over urea is that it is more stable and does not lose nitrogen to the atmosphere. During warm weather, urea should only be applied before imminent rain in order to minimize nitrogen loss.