Denitrification

Nitrates are converted back into nitrogen gas through a process called denitrification. Under anaerobic conditions, such as waterlogged soils, some bacteria are able to use nitrates instead of oxygen during respiration. This is known as anaerobic respiration, and it releases N₂ which can then be fixed again as part of the nitrogen cycle.

NO₃^- → N₂

In agriculture, it’s important to keep soils ploughed and aerated to avoid the loss of nutrients through denitrification.

Figure 1: An overview of denitrification