Nitrogen Cycle

We are also removing large amounts of nitrogen (N2) from the atmosphere faster than the cycle can replace it. This N2 is removed primarily for use in industrial processes that convert it to ammonia (NH3) and ammonium ions (NH4+) used in ferilizers. We upset the nitrogen cycle in aquatic ecosystems by adding excess nitrates (NO3-) to bodies of water through agricultural runoff of ferilizers and animal manure and through discharges from municipal sewage treatment systems. This can cause excessive growth of algae that can disrupt aquatic systems.