The State-of-Science of Soil Carbon Sequestration
Position of the CFAES Rattan Lal Center for Carbon Management and Sequestration (C-MASC)
The Ohio State University, Columbus, OH 43210 USA
The science is clear: soil inputs of biomass carbon derived from plant photosynthesis will increase soil organic carbon sequestration as long as soils are in disequilibrium – until a new balance between carbon inputs and outputs is reached. Increase in organic carbon content of depleted soils will enhance its health and functionality including soil structure or aggregation, water retention and transmission, nutrient reserves and the use efficiency of external inputs. The annual rate of soil organic carbon sequestration differs among climate, landscape position, profile depth and soil properties.
The science is less clear: (i) on the relative importance of biological, chemical and physical processes contributing to soil organic carbon sequestration for the site-specific conditions, (ii) feedbacks between soils and climate, and (iii) on the significance of soil inorganic carbon sequestration.
The strategy is: identifying site-specific soil and land-use management practices which create a positive soil/ecosystem carbon budget and increase inputs of biomass-carbon and especially that of plant roots towards enhancing soil organic carbon sequestration.
Soil organic carbon sequestration has a price tag - farmers, growers, ranchers and forest landowners must be rewarded by carbon credits for implementing and maintaining soil organic carbon sequestering practices for climate and other environmental and societal benefits. Land managers must be rewarded on the basis of the societal value of soil organic carbon through payments for ecosystem services.
31st July 2021