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10.7: Major components of the Nitrogen Cycle

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    Nitrogen Fixation Nitrogen fixation is the microbial conversion of nitrogen gas (N2) to ammonium (NH4+). Various bacteria in plant roots perform this process. Recently, soil microbiologists have reclassified all of the microorganisms that fix nitrogen. The following list provides the new classification of these microbes and the plants that they infect.
    Mineralization Mineralization is the conversion of organic nitrogen to inorganic ammonium (NH4+).
    Nitrification Nitrification is the oxidation of ammonium ions (NH4+) to nitrate ions (NO3-).
    Immobilization Immobilization is the assimilation of ammonium (NH4+) and nitrate (NO3-) into tissue
    Denitrification Denitrification is the reduction of nitrate (NO3-) to nitrogen gases (N2, N2O, NO, and/or NO2) under anaerobic soil conditions (in very wet soil).


    Volatilization is the chemical conversion of ammonium (NH4+) ions to ammonia gas (NH3) in high pH soils and is accelerated by drying of the soil.

    Read through and complete the following activity and questions. All questions should be answered and completed labs are due at the end of the laboratory period. No late work will be accepted.

    This page titled 10.7: Major components of the Nitrogen Cycle is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Anna R. Schwyter & Karen L. Vaughan (UW Open Education Resources (OER)) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.