What process involves the conversion of gaseous nitrogen to ammonia?

The process that involves the conversion of gaseous nitrogen (N₂) into ammonia (NH₃) is known as fixation. This transformation is crucial, as atmospheric nitrogen is generally inert and cannot be utilized directly by most living organisms. Nitrogen fixation typically occurs through biological means, primarily by certain bacteria, including those associated with leguminous plants, or through abiotic processes such as lightning or industrial actions.

The significance of fixation lies in its role in making nitrogen accessible to the ecosystem. Once nitrogen is fixed and converted into ammonia, it can be further processed by soil bacteria into nitrates and nitrites, which then become available to plants. This process supports the nitrogen cycle, which is vital for plant growth and, consequently, the overall health of ecosystems.

Nitrification, denitrification, and assimilation are different processes within the nitrogen cycle but do not involve the conversion of gaseous nitrogen to ammonia. Nitrification is the process where ammonium is converted to nitrates, denitrification is the process where nitrates are reduced back to gaseous nitrogen, and assimilation involves the uptake of nitrates and ammonia by plants.