Ammonium nitrate is the preferred form of nitrogen fertilizer

Ammonium nitrate is a dry granular material manufactured by reacting nitric acid with anhydrous ammonia. The reacted material is concentrated, prilled and coated to prevent caking. In ammonium nitrate, one-half of the nitrogen is in the nitrate form, and the other half is in the ammonium form.

Ammonium nitrate is the preferred form of nitrogen fertilizer when it is to be applied on the soil surface and not incorporated. It does not volatilize as free ammonia, except on high pH soils. Ammonium nitrate use has declined in recent years and is being replaced by urea, which is less expensive and easier to store and maintain. Under the right conditions, ammonium nitrate can become explosive