HR: 08:30h
AN: B11G-03 INVITED    [Abstracts]
TI: Black carbon and organic matter stabilization in soil
AU: * Lehmann, J
EM: CL273@cornell.edu
AF: Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, United States
AU: Liang, B
EM: bl93@cornell.edu
AF: Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, United States
AU: Sohi, S
EM: saran.sohi@bbsrc.ac.uk
AF: Agriculture & the Environment Division, Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
AU: Gaunt, J
EM: jlg84@cornell.edu
AF: Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, United States
AU: Gaunt, J
EM: jlg84@cornell.edu
AF: Agriculture & the Environment Division, Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
AB: Interaction with minerals is key to stabilization of organic matter in soils. Stabilization is commonly perceived to occur due to entrapment in pore spaces, encapsulation within aggregates or interaction with mineral surfaces. Typically only interactions between organic matter and minerals are considered in such a model. Here we demonstrate that black carbon may act very similar to minerals in soil in that it enhances the stabilization of organic matter. Mineralization of added organic matter was slower and incorporation into intra-aggregate fractions more rapid in the presence of black carbon. Added double-labeled organic matter was recovered in fractions with high amounts of black carbon. Synchrotron-based near-edge x-ray fine structure (NEXAFS) spectroscopy coupled to scanning transmission x-ray microscopy (STXM) suggested a possible interaction of microorganisms with black carbon surfaces and metabolization of residues. These findings suggest a conceptual model that includes carbon-carbon interactions and by-passing for more rapid stabilization of litter into what is commonly interpreted as stable carbon pools.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0463 Microbe/mineral interactions
SC: Biogeosciences [B]
MN: 2007 Fall Meeting