Where is most of the nitrogen stored on the biosphere?

Most of the nitrogen in the biOSphere is stored in the atmosphere, which contains about 78% nitrogen gas (N₂). Additionally, significant amounts of nitrogen are found in soil organic matter and in living organisms, particularly in proteins and nucleic acids. While the atmosphere serves as the primary reservoir, the nitrogen cycle facilitates its transfer to soils and biological systems, where it becomes available for use by plants and animals.