Ammonium Nitrate
Ammonium nitrate was the first solid nitrogen (N) fertilizer produced on a large scale, but its popularity has declined in recent years. Consequently, Mosaic does not sell ammonium nitrate; the information below is for educational purposes. It’s been a common N source because it contains both nitrate and ammonium, and it has a relatively high nutrient content.
Chemical properties:
Agricultural use
Ammonium nitrate is a popular fertilizer since it provides half of the N in the nitrate form and half in the ammonium form. The nitrate form moves readily with soil water to the roots, where it’s immediately available for plant uptake. The ammonium fraction is taken up by roots or gradually converted to nitrate by soil microorganisms. Many vegetable growers prefer an immediately available nitrate source of plant nutrition and use ammonium nitrate. Animal farmers like it for pasture and hay fertilization since it’s less susceptible to volatilization losses than urea-based fertilizers when left on the soil surface.
Ammonium nitrate is commonly mixed with other fertilizers, but these mixtures can’t be stored for long periods because of a tendency to absorb moisture from the air. The very high solubility of ammonium nitrate makes it well suited for making solutions for fertigation or foliar sprays.
Non-agricultural uses
A low-density form of prilled ammonium nitrate is widely used as an explosive in the mining industry and on construction sites. Manufacturers intentionally make it porous to allow rapid adsorption of fuel oil (termed “ANFO”).
Instant cold packs are made with two bags—one containing dry ammonium nitrate and the second containing water. When the barrier separating the bags is ruptured, the ammonium nitrate rapidly dissolves in an endothermic reaction, lowering the pack’s temperature to 2 to 3 degrees Celsius within a very short time. Ammonium nitrate is commonly mixed with other fertilizers, but these mixtures can’t be stored for long periods because of a tendency to absorb moisture from the air. The very high solubility of ammonium nitrate makes it well suited for making solutions for fertigation or foliar sprays.
