Nitrogen fixation is the process by which nitrogen is taken from its stable gas form (N2) in air and changes into other nitrogen compounds (such as ammonia, nitrate and nitrogen dioxide) useful for other chemical processes. It is an important part of the nitrogen cycle.
Nitrogen fixation is done four ways:
- Naturally by many different prokaryotes. Micro-organisms that fix nitrogen are called diazotrophs. Some plants and animals (for example, termites), use diazotrophs to live.
- Lightning. NO from nitrogen gas and oxygen gas due to light and lightning, are important for the chemistry of the air, but too small to be important for life.
- Through the Haber-Bosch Process. Nitrogen gas is combined with hydrogen gas into ammonia for fertilizer and explosives.
Biological nitrogen fixation was discovered by Martinus Beijerinck.