How is nitrogen lost from the soil?
Nitrogen is primarily lost by three pathways: • Nitrate leaching happens when excess rainfall moves water through the soil. As the rainwater moves downward in the soil, it carries nitrate nitrogen below the root zone. Nitrate leaching is most likely to occur during wet periods of the year when the crop is not actively growing, such as late fall through early spring. All nitrogen fertilizers convert to nitrate-nitrogen in warm soil. • Ammonia volatilization happens when urea fertilizers and liquid manures are surface-applied. The nitrogen is lost as ammonia to the atmosphere. Volatilization is enhanced when the applied nitrogen coats plant and plant residues without contacting the soil. Nitrogen is also lost as ammonia when anhydrous ammonia injection slots fail to close during application. • Denitrification happens when warm soils are waterlogged for more than a day or two when there is nitrate in the soil. These conditions are most likely to occur during wet spells in May or June. Dur
