EDAFOLOGIA, Vol. 11 (1), pp.37-43, 2004
REDOX, SOILS, AND CARBON SEQUESTRATION
W. CHESWORTH
University of Guelph, Guelph, Ontario, Canada.
One of the ecological functions of soil is to act as a short term carbon reservoir through which CO2 passes from gas to solid as a result of the process of photosynthesis, then back to gas by oxidation of the solid forms. How long the carbon resides in the soil as solid organic matter is a function, amongst other factors, of redox potential. The issue is examined here in the context of a series of Eh-pH diagrams. This leads to the overall conclusion that controlling the level of atmospheric CO2 by soil-management practices compares unfavourably with other techniques, and cannot be considered as other than a stop-gap measure.