Nitrogen fixation is

Nitrogen fixation is Nitrogen ⟶ Ammonia and Nitrogen ⟶ Nitrates.
Nitrogen fixation or Biological Nitrogen Fixation (BNF) is a chemical process by which molecular nitrogen (N₂), which has a strong triple covalent bond, is converted into ammonia (NH₃) or related nitrogenous compounds like nitrates.
The production of the nitrogenase complex is genetically regulated, and the activity of the protein complex is dependent on ambient oxygen concentrations, intracellular and extracellular concentrations of ammonia and oxidized nitrogen species (nitrate and nitrite).