Olson also recommends that the definition of SOC sequestration include a reference to the land unit. "Soil organic carbon sequestration is currently defined as the process of transferring CO₂ from the atmosphere into the soil through plants, plant residues, and other organic solids that are stored or retained as part of the soil organic matter (humus). The retention time of sequestered carbon in the soil (terrestrial pool) can range from short-term (not immediately released back to the atmosphere) to long-term (millennia) storage," Olson said. The SOC sequestration process should increase net SOC storage during and at the end of a study to above the previous pre-treatment baseline levels and result in a net reduction in the atmospheric CO₂ levels. I believe that the phrase 'of a land unit' needs to be added to the definition to add clarity and to exclude the loading or adding of organic C derived naturally or artificially from external sources," Olson suggested.
Olson concluded by saying that carbon not directly from the atmosphere and from outside the land unit should not be counted as sequestered SOC. The definition of SOC sequestration as defined with borders would mean any C already in storage and transported or redistributed to the plot area or field would have to be accounted for and does not qualify as sequestered SOC.
"Any manure from outside the plot area or SOC-rich sediments transported and deposited from adjacent upland are just redistributed or transported C and not really sequestered SOC," Olson said. "That C was alrea
|Contact: Debra Levey Larson|
University of Illinois College of Agricultural, Consumer and Environmental Sciences