(NH3). The bacteria use some of the ammonia they produce as a nutrient and excrete the rest of the soil or water. Some ammonia is converted to ammonium ions (NH4+) that can be used as a nutrient by plants.
2. We add nitrous oxide (N2O) to the atmosphere through the action of anaerobic bacteria on livestock wastes and commercial inorganic fertilizers applied to the soil. This greenhouse gas can warm the atmosphere and deplete the stratospheric ozone.
3. We release large quantities of nitrogen stored in soils and plants as gaseous compounds into the atmosphere through destruction of forests, grasslands, and wetlands.
4. We upset the nitrogen cycle in aquatic ecosystems by adding excess nitrates to bodies of water through agricultural runoff and discharges from municipal sewage systems.
5. We remove nitrogen from topsoil when we harvest nitrogen-rich crops, irrigate crops, and burn and clear grasslands and forests before planting crops.