Nitrogen fixation
Nitrogen enters the living world from the atmosphere via nitrogen-fixing bacteria. This nitrogen and nitrogenous waste from animals is then processed back into gaseous nitrogen by soil bacteria, which also supply terrestrial food webs with the organic nitrogen they need.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Biogeochemical Cycles. October 17, 2013."
http://cnx.org/content/m44889/latest/Figure_46_03_06.png
OpenStax CNX
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