Nitrification is the process by which ammonia (NH3) is converted into nitrite (NO2-) and then into nitrate (NO3-), primarily carried out by bacteria.
The process by which organic nitrogen compounds are converted into ammonia.
Nitrogen fixation: The conversion of atmospheric nitrogen gas (N2) into forms usable by plants, such as ammonium ions (NH4+).
Nitrogen cycle: The continuous movement and transformation of nitrogen through various biotic and abiotic processes in ecosystems.