Does soil really hold much carbon?
Soils are estimated to contain about 75% of all terrestrial carbon. Because 25 billion tons of soils are lost through wind and water erosion each year, there is an incentive to prevent erosion not only to benefit agriculture but also to increase carbon sequestration. One solution is to produce and protect soils high in carbon-containing organic matter because they have better texture and are better able to absorb nutrients, retain water, and resist erosion. Source: Oak Ridge National Laboratory (ORNL) http://www.ornl.gov/info/ornlreview/rev32_3/earth.
