HR: 10:50h
AN: B12B-03    [Abstracts]
TI: A soil organic matter model based on measurable pools for use in incubation studies
AU: * De Gryze, S
EM: sdegryze@ucdavis.edu
AF: Department of Plant Sciences, UCDavis, One Shields Avenue, mail stop 1 Davis, CA 95616, Davis, CA 95616,
AU: Six, J
EM: jwsix@ucdavis.edu
AF: Department of Plant Sciences, UCDavis, One Shields Avenue, mail stop 1 Davis, CA 95616, Davis, CA 95616,
AB: The current generation of soil organic matter (SOM) models is based on conceptual pools. No analytical method exists to measure the amount of C stored in the separate pools of a real-world soil sample. We propose a new SOM model which is based on measurable SOM pools. These pools can be extracted using physical fractionation techniques such as wet sieving, micro-aggregate isolation, flotation, and dispersion. We distinguish the dynamics of SOM enclosed in macro-aggregates, micro-aggregates enclosed within macro-aggregates, free micro-aggregates and SOM outside of any aggregates, as demonstrated in Six et al., 2004. In addition, the dynamics of particulate and mineral associated organic matter are followed. Simultaneously, aggregate formation and breakdown are simulated. Aggregates dynamics are dependent on microbial activity. As a consequence, the feedback between soil structure and soil organic matter is explicitly integrated. The model concepts will be presented together with a calibration, and confrontation with measured data from incubation studies.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0466 Modeling
SC: Biogeosciences [B]
MN: 2007 Fall Meeting