The cycling of various forms of biologically available nitrogen through the plant, animal, and microbial worlds (kingdoms) as well as the atmosphere and geosphere.
The process of decomposing certain waste products by bacterial action. The consists of the following: a. Decomposition of animal protein by bacteria, converting it into its amino acids. b. The amino acids are further broken down into ammonia. c. The ammonia combines with carbon dioxide to form ammonium carbonate, which is then connected to nitrites. d. Nitrites combine with sodium and potassium, being converted into nitrates by nitrobacters. e. Nitrates that are dissolved in water diffuse into the root systems of plants, combining with carbon dioxide and water to form plant proteins. The plant proteins are eaten by animals and converted into animal proteins.
A natural cycle in which nitrogen is discharged from animal life into the soil; it is then taken up from soil into plants for their nourishment; and in turn nitrogen returns to animal life through plants eaten.