12:36 PM - 12:39 PM
[MIS03-P11] Soil organic matter and aggregate hierarchy revisied: a case study using an Andisol
3-min talk in an oral session
The next key question is how the particle-size fractions isolatable after the maximum dispersion are assembled together to form the shaking-resistant aggregates of different density. We attempted to answer this question by examining the organic and inorganic chemistry (C, N, 13C, 15N, d14C, 13C-NMR, extractable metals) and the surface characteristics (SSA by N2-BET and XPS) of the size and density fractions. We will also discuss the nature of organo-mineral interactions inferred from our results and compare it with the previously-suggested concepts such as aggregate hierarchy (Tidall and Oades, 1982), and "zonal layering" model (Kleber et al. 2007).
Asano, M and Wagai, R. (2014) Evidence of aggregate hierarchy at micro- to submicron scales in an allophanic Andisol. Geoderma. 216, 62-74.
Kleber, M. et al. (2007) A conceptual model of organo-mineral interactions in soils: self-assembly or organic molecular fragments into zonal structures on mineral surfaces. Biogeochem. 85: 9-24.
Tisdall, J.M. and Oades, J.M. (1982) Organic-matter and water-stable aggregates in soils. J. Soill Sci. 33: 141-163.
Wagai, R. et al. (2015) Nature of soil organo-mineral assemblage examined by sequential density fractionation with and without sonication: Is allophanic soil different? Geoderma 241-242: 295-305.