How is nitrogen recycled?
1 Answer
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Gaseous nitrogen (78% in air) is fixed (by nitrogen fixing bacteria, and during lightning), then absorbed and assimilated by plants in the form of proteins, as well as nucleic acids.
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All consumers avail nitrogen directly or indirectly from plants.
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Nitrogen is returned to soil with excretory materials of animals and dead organisms.
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Organic nitrogen now undergoes ammonification (formation of ammonia from organic nitrogen) and nitrification (oxidation of ammonia into nitrite and then to nitrate) by soil microbes. Nitrates are thus produced which could be reused by producers.
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Denitrification of nitrates by bacteria again releases nitrogen in gaseous form to the atmosphere.
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Various groups of bacteria and fungi are involved in nitrogen cycle.
A very brief representation of the nitrogen cycleis given below:-
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