The process by which bacteria (less often other organisms) convert atmospheric nitrogen into organic compounds that can be taken up by plants. This process often takes place in specialised nodules.
Conversion of atmospheric nitrogen (N2 gas) into a soluble, biologically available form. The conversion is carried out by nitrogen-fixing organisms (e.g., Rhizobium bacteria) which live symbiotically in the roots of certain plants, e.g., alfalfa or soybeans. This is one of nature’s ways of fertilizing. When not enough nitrogen fixation occurs, soil is not able to produce maximum crop yields and farmers may need to spread fixed nitrogen onto the field in the form of the fertilizer ammonium nitrate or sodium nitrate.
The conversion of atmospheric nitrogen into nitrates through the action of bacteria in the soil.