Definitions for "Nitrogen fixation"
The process by which nitrogen gas from the atmosphere is converted into ammonia. The transformation is energy requiring and can be achieved industrially through the Haber Bosch process or by specific microorganisms -- all bacteria.
biological assimilation of atmospheric nitrogen to form organic nitrogen-containing compounds.
The absorption of nitrogen from the atmosphere by bacteria in the soil. When the bacteria die, they release the nitrogen into the soil rather than back into the atmosphere, and plants can then use it as a nutrient.