Nitrogen forms 78% i.e. the maximum portion of the atmosphere. It is necessary for the maintenance of the cycle of nature.
The circulation and recycling of nitrogen gas into the form of different compounds through various biotic and abiotic processes in nature is called the nitrogen cycle.
All organisms participate in the nitrogen cycle. It is an important component of proteins and nucleic acids.
As compared to other elements, it is inactive and does not easily combine with other elements.
Most organisms cannot use the free form of nitrogen.
Important processes of nitrogen cycle:
(a) Nitrogen fixation: Conversion of nitrogen into nitrates and nitrites through atmosphere, industrial and biological processes.
(b) Ammonification: Release of ammonia through the decomposition of dead bodies and excretory wastes of organisms.
(c) Nitrification: Conversion of ammonia into a nitrite and then nitrate.
(d) Denitrification: Conversion of nitrogen compounds into gaseous nitrogen.
