Soil Conditions

Soil characteristics that affect the accumulation of carbon include the soil order (type), soil texture, drainage, and acidity.¹

The soil order reflects the native environment under which the soil was formed, and this can be helpful in determining the soil's innate capacity to sequester organic carbon under ideal conditions.

Soil texture is indicative of the aggregate structure of soil and its moisture-holding capacity.² In continuously wet soils with limited oxygen capacity, such as those found in wetlands, and areas of poor drainage, an ideal setting is provided for slowing decomposition, thereby increasing the carbon stock.³

Further, research indicates that soil wetness as indicated by drainage classes is an ideal indicator of organic carbon accumulation.⁴

Soil acidity is presumed to play an important role in the accumulation and decomposition of organic matter in soils. While some soil scientists have observed organic matter accumulating faster in acidic soils,⁵ others have observed carbon accumulating in moderate acidity to slightly alkaline soil conditions (pH 5.6-7.8).¹

References:

1. Cihacek, L.J., Personal communications, 2004.
2. Johnson, C.M., Zarin, D.J., and Johnson, A.H., 2000, Post-disturbance aboveground biomass accumulation in global secondary forests: Ecology, v. 81, p. 1395-1401.
3. Paustian, K.H., and Cole. C.V., 1998, CO₂ mitigation by agriculture - an overview: Climatic Change, v. 40, p. 135-162.
4. Davidson, E A., 1995, Spatial covariation of soil organic carbon, clay content, and drainage class at a regional scale: Landscape Ecology, v. 10, no. 6, p. 349-362.
5. Collins, M.E., and Kuehl, R.J., 2001, Organic matter accumulation and organic soils in wetland soils genesis, hydrology, landscapes, and classification: Lewis Publishers, p. 1-417.