ARS | Publication request: SOIL ORGANIC MATTER STRATIFICATION RATIO AS AN INDICATOR OF IMPORTANT SOIL FUNCTIONS

Submitted to: Southern Association of Agricultural Scientists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 4, 2002
Publication Date: February 4, 2002
Citation: Franzluebbers, A.J. 2002. Soil organic matter stratification ratio as an indicator of important soil functions. Southern Association of Agricultural Scientists Proceedings.

Technical Abstract: Soil quality is a concept based on the premise that management can deteriorate, stabilize, or improve soil ecosystem functions. Soil organic matter is a key component of soil quality by providing the energy, substrates, and biological diversity to support biological activity, which affects (1) aggregation, infiltration, and decomposition. Lack of residue cover and exposure of soil to high-intensity rainfall result in poor aggregation, reduced plant water availability, erosion, and off-site impacts of sedimentation and poor water quality. It is hypothesized that the degree of stratification of soil organic C and N pools with soil depth, expressed as a ratio, could indicate soil quality or soil ecosystem functioning. Greater stratification of soil C and N pools with the adoption of conservation tillage under inherently low soil organic matter conditions (i.e., warmer climatic regime or coarse-textured soil) suggests that the total standing stock of soil organic matter alone is a poor indication of soil quality. Experimental data demonstrated the close relationship between soil organic C stratification ratio and (1) infiltration, (2) soil stability exposed to water, and (3) soil porosity of the surface 0-3 cm.