Nutrient transformation
Nutrient transformation a range of soil biological processes which lead to changes in the chemical or physical status of nutrient resources (excluding assimilation). These processes are: mineralisation, N transformations, S transformations and fragmentation. Mineralisation involves the transformation of organic nutrients to inorganic form by soil bacteria and fungi. While the cycling of P, Mg, K and Ca in soil is predominantly governed by chemical processes, soil (micro)biology plays a large role in the transformation of N and S. N transformations include the sub-processes: nitrification, denitrification[1], dissimilatory nitrate reduction to ammonium (DNRA)[2], anaerobic ammonium oxidation (Anammox)[3], and volatilisation[4], which are all performed by microorganisms. S transformations include the microbial processes sulphur oxidation and sulphate reduction[5].
[1] Robertson GP & Groffman PM. 2007. Nitrogen Transformations, in: Paul, E.A. (Ed.), Soil Microbiology, Ecology and Biochemistry (Third Edition). Academic Press, San Diego, pp. 341–364.
[2] Rütting T et al. 2011. Assessment of the importance of dissimilatory nitrate reduction to ammonium for the terrestrial nitrogen cycle. Biogeosciences 8: 1779–1791.
[3] Hu B et al. 2011. Anaerobic ammonium oxidation (anammox) in different natural ecosystems. Biochemical Society Transactions 39: 1811–1816.
[4] Fenn LB & Hossner LR. 1985. Ammonia Volatilization from Ammonium or Ammonium-Forming Nitrogen Fertilizers. Springer, New York, NY, pp. 123–169.
[5] Brown KA. 1982. Sulphur in the environment: A review. Environmental Pollution Series, Chemical and Physical 3: 47–80.