Key soil functional properties affected by soil organic matter - evidence from published literature

Soil Change Matters 2014

Murphy, Brian^1

NSW Office of Environment and Heritage, Department of the Environment, Australian Grains Research and Development Corporation, Cowra

NSW, Australia^1

关键词: Aggregate stability;    Buffering capacities;    Cation exchange capacities;    Functional properties;    Literature search;    Pedo-transfer functions;    Soil organic carbon;    Soil organic matters;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/25/1/012008/pdf
DOI  :  10.1088/1755-1315/25/1/012008

来源: IOP

【 摘 要 】

The effect of varying the amount of soil organic matter on a range of individual soil properties was investigated using a literature search of published information largely from Australia, but also included relevant information from overseas. Based on published pedotransfer functions, soil organic matter was shown to increase plant available water by 2 to 3 mm per 10 cm for each 1% increase in soil organic carbon, with the largest increases being associated with sandy soils. Aggregate stability increased with increasing soil organic carbon, with aggregate stability decreasing rapidly when soil organic carbon fell below 1.2 to 1.5 5%. Soil compactibility, friability and soil erodibility were favourably improved by increasing the levels of soil organic carbon. Nutrient cycling was a major function of soil organic matter. Substantial amounts of N, P and S become available to plants when the soil organic matter is mineralised. Soil organic matter also provides a food source for the microorganisms involved in the nutrient cycling of N, P, S and K. In soils with lower clay contents, and less active clays such as kaolinites, soil organic matter can supply a significant amount of the cation exchange capacity and buffering capacity against acidification. Soil organic matter can have a cation exchange capacity of 172 to 297 cmol(+)/kg. As the cation exchange capacity of soil organic matter varies with pH, the effectiveness of soil organic matter to contribute to cation exchange capacity below pH 5.5 is often minimal. Overall soil organic matter has the potential to affect a range of functional soil properties.