How Long Does Ammonia Nitrate Stay in the Soil?

Plants Only Use Inorganic Nitrogen

• Nitrogen is added to the soil to help plants grow healthy. Nitrate is a naturally occurring soil mineral. Plants cannot absorb pure, organic nitrogen. The nitrogen must be converted into inorganic forms of nitrate for plant use. Usually, biological microbes in the soil break organic nitrogen down into inorganic forms. Bypassing the organic process is why chemical nitrates, like ammonia nitrates, work so well in growing plants swiftly.

Chemical Nitrogen Fertilizers

• An ample supply of nitrogen is necessary for optimum plant growth and chemical fertilizers have been used to achieve this goal. Often, chemical nitrogen fertilizer is in the form of ammonium nitrogen and in the soil it rapidly converts to usable nitrate. The crop growth is relatively the same whether the chemicals are ammonium, ammonia or nitrate. Ammonium sulfates, ammonium phosphates, different nitrate salts, ammonium nitrate, urea and other organic nitrogen sources can be found mixed in to make up the chemical fertilizer versions.

The Problem with Nitrates

• When an extreme build up of nitrate levels are present in the soil, toxic situations can occur. This potential toxicity can happen with chemical as well as organic nitrogen sources. Chemical nitrogen, such as ammonia nitrate, is known to cause contaminated soil levels when used in large volumes. Great amounts of organic nitrogen, such as non-composted animal manure, are just as equally guilty of tainting the soil. Ammonia nitrogen is stored in the soil where nitrates can leach from the soil into the atmosphere and water sources.

Bacteria Converts Ammonia Nitrate

• Soil microorganisms are the superheroes that change all nitrogen into an inorganic nitrate that plants can assimilate. The ammonia source of nitrogen is especially held in clay until it is set free by bacterial action. Kitchen compost or spent mushroom compost can be excellent soil amendments with the necessary active bacteria to make excess nitrogen available for plant use. Where there is a concern for organic gardening and chemical nitrogen is suspected in the soil, non-edible cover crops can be grown to convert the chemical fertilizers from the soil.