Principal Investigator:
Garrison
Sposito
Professor and Chemist in the A.E.S. Division of Ecosystem Sciences
University of California
Berkeley, CA 94720
Duration of the Project: 2 years
This project will investigate the hypothesis that smectite clay
minerals can sequester soil humus effectively against microbial oxidation by
a mechanism that involves the encapsulation of alkyl compounds in fulvic acid,
with subsequent movement of the alkyl-fulvic acid complex into smectite interlayers,
where the alkyl component is then protected against microbial attack by hydrophobic
interactions. Laboratory experiments will be conducted to determine the chemical
conditions under which this scenario can be realized and to develop methods
of evaluating the robustness of the resulting interlayer complex. Both specimen
and naturally-occurring humus-clay complexes will be studied. The results are
expected to provide mechanistic insight as to how carbon can be sequestered
more effectively in California soils and how these soils can be managed to enhance
their content of recalcitrant organic matter.