The nitrogen cycle illustrates the relationship between different forms of nitrogen in the soil, water, air, and living organisms. It is considered to be a cycle since nitrogen moves around from place to place in different forms but is always…

1. Nitrogen Fixation The first stage in the nitrogen cycle is the reduction of N2 gas to ammonia, a process called nitrogen fixation. Reaction:  N2 + 3 H2 –> <– 2 NH3 2. Nitrification                             Nitrosomonas                                    Nitrobacter              [NH4+]    ————————— >   NO2- …

The movement of nitrogen between the atmosphere, biosphere, and geosphere in different forms is called the nitrogen cycle and is one of the major biogeochemical cycles.