Immobilization (soil science): Difference between revisions
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==C:N Ratio== |
==C:N Ratio== |
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Whether nitrogen is mineralized or immobilized depends on the C/N ratio of the plant residues.iii<ref>R.G. McLaren & K. Cameron ''Soil Science: Sustainable production and environmental protection'' (2nd edition), Oxford University Press, (1996) {{ISBN|0-19-558345-0}}</ref> For example, incorporating materials high in carbon to nitrogen ratio such as saw dust and straw will stimulate soil microbial activity,increase demand for nitrogen, leading to immobilization. <ref>{{Cite journal|last=Szili-Kovács|first=Tibor|last2=Török|first2=Katalin|last3=Tilston|first3=Emma L.|last4=Hopkins|first4=David W.|date=2007-08-01|title=Promoting microbial immobilization of soil nitrogen during restoration of abandoned agricultural fields by organic additions|url=https://doi.org/10.1007/s00374-007-0182-1|journal=Biology and Fertility of Soils|language=en|volume=43|issue=6|pages=823–828|doi=10.1007/s00374-007-0182-1|issn=1432-0789}}</ref> In general plant residues entering the soil have too little nitrogen for the soil microbial population to convert all of the carbon into their cells. If the C:N ratio of the decomposing plant material is above about 30:1 the soil microbial population may take nitrogen in mineral form (e.g. [[nitrate]]). This mineral nitrogen is said to be immobilized. This may cause nitrogen deficiency in plants growing in the soil. |
Whether nitrogen is mineralized or immobilized depends on the C/N ratio of the plant residues.iii<ref>R.G. McLaren & K. Cameron ''Soil Science: Sustainable production and environmental protection'' (2nd edition), Oxford University Press, (1996) {{ISBN|0-19-558345-0}}</ref> For example, incorporating materials high in carbon to nitrogen ratio such as saw dust and straw will stimulate soil microbial activity,increase demand for nitrogen, leading to immobilization. <ref>{{Cite journal|last=Szili-Kovács|first=Tibor|last2=Török|first2=Katalin|last3=Tilston|first3=Emma L.|last4=Hopkins|first4=David W.|date=2007-08-01|title=Promoting microbial immobilization of soil nitrogen during restoration of abandoned agricultural fields by organic additions|url=https://doi.org/10.1007/s00374-007-0182-1|journal=Biology and Fertility of Soils|language=en|volume=43|issue=6|pages=823–828|doi=10.1007/s00374-007-0182-1|issn=1432-0789}}</ref>. This is known as [[Priming (agriculture)|primin]]<nowiki/>g effect <ref>{{Cite journal|last=Bastida|first=Felipe|last2=García|first2=Carlos|last3=Fierer|first3=Noah|last4=Eldridge|first4=David J.|last5=Bowker|first5=Matthew A.|last6=Abades|first6=Sebastián|last7=Alfaro|first7=Fernando D.|last8=Asefaw Berhe|first8=Asmeret|last9=Cutler|first9=Nick A.|last10=Gallardo|first10=Antonio|last11=García-Velázquez|first11=Laura|date=2019-08-02|title=Global ecological predictors of the soil priming effect|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6677791/|journal=Nature Communications|volume=10|doi=10.1038/s41467-019-11472-7|issn=2041-1723|pmc=6677791|pmid=31375717}}</ref> In general plant residues entering the soil have too little nitrogen for the soil microbial population to convert all of the carbon into their cells. If the C:N ratio of the decomposing plant material is above about 30:1 the soil microbial population may take nitrogen in mineral form (e.g. [[nitrate]]). This mineral nitrogen is said to be immobilized. This may cause nitrogen deficiency in plants growing in the soil. |
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As carbon dioxide is released via decomposition the C:N ratio of the organic matter decreases, and the microbial demand for mineral nitrogen is decreased. When the C:N ratio falls below about 25:1 further decomposition results in simultaneous mineralization of nitrogen which is in excess to that required by the microbial population. |
As carbon dioxide is released via decomposition the C:N ratio of the organic matter decreases, and the microbial demand for mineral nitrogen is decreased. When the C:N ratio falls below about 25:1 further decomposition results in simultaneous mineralization of nitrogen which is in excess to that required by the microbial population. |
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Revision as of 23:25, 20 November 2019
Immobilization in soil science is the conversion of inorganic compounds to organic compounds by micro-organisms or plants, by which it is prevented from being accessible to plants.[1] Immobilization is the opposite of mineralization.Immobilization in soil science is the conversion of inorganic compounds to organic compounds by micro-organisms or plants, by which it is prevented from being accessible to plants.[1,[2] Immobilization is the opposite of mineralization where the inorganic nutrients are taken up by soil microbes making them unavailable for plant uptake.[2] Immobilization process is a biological process controlled by bacteria[3]
C:N Ratio
Whether nitrogen is mineralized or immobilized depends on the C/N ratio of the plant residues.iii[4] For example, incorporating materials high in carbon to nitrogen ratio such as saw dust and straw will stimulate soil microbial activity,increase demand for nitrogen, leading to immobilization. [5]. This is known as priming effect [6] In general plant residues entering the soil have too little nitrogen for the soil microbial population to convert all of the carbon into their cells. If the C:N ratio of the decomposing plant material is above about 30:1 the soil microbial population may take nitrogen in mineral form (e.g. nitrate). This mineral nitrogen is said to be immobilized. This may cause nitrogen deficiency in plants growing in the soil.
As carbon dioxide is released via decomposition the C:N ratio of the organic matter decreases, and the microbial demand for mineral nitrogen is decreased. When the C:N ratio falls below about 25:1 further decomposition results in simultaneous mineralization of nitrogen which is in excess to that required by the microbial population.
When decomposition is virtually complete soil mineral nitrogen will be higher than it was initially due to mineralization of the plant residue nitrogen.
References
- ^ Principles and Practices of Soil Science, the soil as a natural resource (4th edition), R.E. White
- ^ a b "Immobilization". lawr.ucdavis.edu. Retrieved 2019-11-20.
- ^ Schimel, D. S. (1988-10-01). "Calculation of microbial growth efficiency from15N immobilization". Biogeochemistry. 6 (3): 239–243. doi:10.1007/BF02182998. ISSN 1573-515X.
- ^ R.G. McLaren & K. Cameron Soil Science: Sustainable production and environmental protection (2nd edition), Oxford University Press, (1996) ISBN 0-19-558345-0
- ^ Szili-Kovács, Tibor; Török, Katalin; Tilston, Emma L.; Hopkins, David W. (2007-08-01). "Promoting microbial immobilization of soil nitrogen during restoration of abandoned agricultural fields by organic additions". Biology and Fertility of Soils. 43 (6): 823–828. doi:10.1007/s00374-007-0182-1. ISSN 1432-0789.
- ^ Bastida, Felipe; García, Carlos; Fierer, Noah; Eldridge, David J.; Bowker, Matthew A.; Abades, Sebastián; Alfaro, Fernando D.; Asefaw Berhe, Asmeret; Cutler, Nick A.; Gallardo, Antonio; García-Velázquez, Laura (2019-08-02). "Global ecological predictors of the soil priming effect". Nature Communications. 10. doi:10.1038/s41467-019-11472-7. ISSN 2041-1723. PMC 6677791. PMID 31375717.