Nitrification

• Nitrification is a two-stage process, note Killpack and Buchholtz. First, soil microorganisms called nitrosomonas convert ammonia to nitrite. Then a soil microorganism named nitrobacter changes nitrite to nitrate. Nitrate is a form of nitrogen that is easily carried in water to plant roots. Organic matter, water content, oxygen supply, temperature and soil pH all affect the nitrification process.
  
  

The Nitrogen Cycle

• The nitrogen cycle--the conversion of ammonia to nitrate--is important to crop producers, states Mike Rankin of the University of Wisconsin Extension. Rather than being washed out of soil, ammonia sources bond with soil--a process called denitrification--in heavy rains. For this reason, ammonia and nitrate contents in soil are exceptionally important, as soils that are high in nitrate only are at constant risk of denitrification from precipitation.
  
  

Nitrification Inhibitors

• Crop producers employ nitrification inhibitors to retain ammonia sources and combat denitrification. Nitrification inhibitors are only employed when situations denote their use, as nitrification inhibitors only upset the nitrogen cycle in well-drained soils with sufficient nitrogen stores. Rankin recommends the use of nitrification inhibitors only with sandy, poorly drained soils or when nitrogen fertilizers are applied in rainy periods.
  
  

Benefits of Nitrification

• Nitrification is only active in warm, moist soils. In much of the US, this means nitrification is experienced in spring and summer, is slow in fall and is nearly non-existent in winter, report Killpack and Buchholtz. Nitrification allows for nitrogen-rich water delivery to plant root systems. Nitrogen is a macronutrient (which is an important nutrient necessary for plant growth including phosphorous and potassium) in addition to nitrogen--and is exceptionally important in plant growth.
  
  

Water Quality Impact

• Denitrification has an impact on water quality. Once nitrogen is converted, it is easily transported to ground water in high-drainage--usually sandy--soil, according to Killpack and Buchholtz. Nitrogen toxicity in water is especially dangerous for infants less than one year old and young or pregnant animals. Nitrogen poisoning causes anoxia (internal suffocation) and common infant symptoms include bluish skin especially around the eyes and mouth. Boiling nitrogen-contaminated water increases contaminant levels.