The nitrogen cycle
Nitrogen cycle - biogeochemical nitrogen cycle. Its most of it is due to the action of living beings. The soil microorganisms that provide nitrogen exchange of soil are played in a very large role in the cycle, which is present there in the form of a simple substance and ions: nitrites, nitrates and ammonium. The concentrations of these ions reflect the state of the soil communities, since these indicators affect the state of the biota (plants, microflora), the state of the atmosphere, washing out of the soil of various substances.