Information on Nitrogen Additives in Soil

Nitrogen Fixation

• Most plants cannot access the nitrogen in the atmosphere; however, legumes are an exception to the rule. These plants are capable of transforming atmospheric nitrogen into a form of nitrogen that is available to other plants for use. When the legumes die and decompose, plant-usable nitrogen is added to the soil for other plants to take advantage of. This crop rotation using legumes is an important part of the agricultural process on most modern farms.

Crop Residue

• Plants that aren't legumes can also work as a nitrogen additive, but results in the soil can take a long time to appear. These plants contain nitrogen that has been used to help form them, nitrogen that must be broken down to a simpler form before it is again plant-available.

Organic Matter

• Organic matter is an effective slow-release way of adding nitrogen to the soil in a sustainable manner. Organic matter is teeming with nitrogen, and generally is also full of microorganisms that make that nitrogen plant-available as necessary and effectively recycle nitrogen that is added to the soil to make it available to plants. Organic matter also helps to prevent the leeching of nitrogen from the soil as a result of erosion or from other factors. It does this by stabilizing the texture of the soil and maintaining nitrogen within microorganisms as opposed to loose in the soil.

Commercial Fertilizers

• The nitrogen used in commercial fertilizers is derived from the atmosphere just like the nitrogen provided by legumes. It is made into plant-available form by combining N 2 in the air with hydrogen (H 2) to form ammonia, one of two forms in which nitrogen is available to plants. These nitrogen additives are available in a number of forms, slow release or with instant results, liquid or granular form, with many different concentrations available. If you choose to use one of these products to add nitrogen to your yard, be sure to consult your local garden center or cooperative extension service beforehand to find out what fertilizer is best suited to your needs. Improper use of commercial nitrogen additives can burn up your plants or leech into nearby water sources and damage the ecosystem.