Why is controlling nitrogen important?
Nitrogen (particularly nitrate) has been identified as a major concern in ground and surface water contamination. In addition, the emission of excess ammonia into the air from agriculture can contribute to increased nitrogen deposition from rainfall. When nitrogen is applied to the land in correct amounts and at proper times, it poses little environmental risk because plants require nitrogen for growth. However, excess nitrogen (applied through manure, commercial fertilizer, or even from decomposing organic matter) serves as a substrate for microorganisms, which convert nitrogen to ammonium ions. Some ammonium ions are released into the atmosphere as ammonia, but when this happens outdoors, concentrations are rarely detectable by humans. Non-volatilized ions are further oxidized to nitrate, which can potentially leach through the soil and contaminate ground water. Nitrates can also contaminate surface water by direct runoff into waterways.
