Final answer:
Nitrogen fixation is the process where atmospheric nitrogen (N2) is converted into reactive forms such as ammonia or nitrate. This can happen biologically through bacteria in soil and plant roots, or abiotically through lightning which aids in forming nitrogen oxides that become nitrates.
Step-by-step explanation:
Nitrogen fixation is the process in which the N2 compound in the atmosphere breaks and combines with other compounds. The nitrogen is fixed when it combines with hydrogen or oxygen. Nitrogen fixation is crucial because atmospheric nitrogen, consisting of N2 molecules, is inert due to a strong triple bond that makes it unavailable to most organisms. Through nitrogen fixation, nitrogen is converted into more reactive forms like ammonia (NH3) or nitrate (NO3-), which living organisms can utilize for growth and development. This process can occur biologically, in soil or plant roots with the help of bacteria, or abiotically, through phenomena such as lightning which causes nitrogen to react with oxygen forming nitrogen oxides that dissolve in rain to form nitrates.
Notably, atmospheric fixation by lightning contributes to a part of the natural nitrogen fixation, while biological nitrogen fixation conducted by bacteria plays a significant role in the nitrogen cycle within terrestrial ecosystems.