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Turnover of intra- and extra-aggregate organic matter at the silt-size scale

Informally Refereed

Abstract

Temperate silty soils are especially sensitive to organic matter losses associated to some agricultural management systems. Long-term preservation of organic C in these soils has been demonstrated to occur mainly in the silt- and clay-size fractions, although our knowledge about the mechanisms through which it happens remains unclear. Although organic matter in such fractions is usually assumed to be present in the form of organo-mineral complexes, a large percentage of this fraction appears to be micro-aggregated. In this study we hypothesized that slaking-resistant silt-size aggregates should be preferential sites of long-term organic matter preservation in soils, by physical entrapment that would allow for stabilization by interaction with mineral surfaces.

Keywords

soil aggregation, organic matter turnover, 13C, microaggregates, size and density fractionation

Citation

Virto, I.; Moni, C.; Swanston, C.; Chenu, C. 2010. Turnover of intra- and extra-aggregate organic matter at the silt-size scale. Geoderma. 156: 1-10.
Citations
https://www.fs.usda.gov/research/treesearch/34849