Most of the available nitrogen in soil is in the nitrate form, since ammonium nitrogen is converted relatively quickly to nitrate by soil bacteria. The nitrogen in the fertilizer materials discussed in this Factsheet is present in one or both of these forms, or is quickly converted to either the ammonium or nitrate form in the soil. In their manufacture, natural gas is first reacted with nitrogen gas from the atmosphere to produce ammonia, which is then used as the raw material in making other nitrogen materials. All are effective in supplying nitrogen for crops when used properly, but they differ in cost, safety, convenience, equipment requirements and compatibility with other products. Because it requires the least amount of manufacturing, it is also the least costly source.
Ammonia is very alkaline and very caustic.
Because it attracts water, ammonia will draw moisture from tissues, causing a burning effect. Body tissues that have a high moisture content, such as the eyes, lungs, and linings of the nose and throat, are especially vulnerable. Even relatively low concentrations of ammonia in the air can cause irritation and damage to these tissues. At high concentrations, ammonia causes death by suffocation. Always wear protective clothing when handling anhydrous ammonia.