The primary human-related sources of N2O are:

• agricultural soil management: N2O is produced naturally in soils through the microbial processes, but these natural emissions of N2O can be increased by the use of synthetic and organic fertilizers, production of nitrogen-fixing crops and the application of livestock manure to croplands and pasture.
• animal manure management
• sewage treatment
• mobile and stationary combustion of fossil fuel: N2O is a product of the reaction that occurs during fossil fuel combustion.
• adipic acid production.

Nitrous oxide is also produced naturally from a wide variety of biological sources in soil and water, particularly microbial action in wet tropical forests. N2O is naturally produced during the bacterial breakdown of nitrogen in soils and in the earth's oceans. Globally, tropical soils and oceans account for over 70% of the natural sources.

Nitrous oxide formula