Conservation Strategies for Improving Soil Quality and Organic Matter Storage
D. L. Karlen, C. A. Cambardella
Abstract
This chapter reviews some of the characteristics of the soil C pool and to suggest how changes in this pool may affect global warming. Potential effects of four management strategies: Conservation tillage; Cover cropping; Crop rotations; and Manure and fertilizer applications are then discussed with regard to how they might affect the soil C pools, soil quality, the processes that determine whether a soil is functioning as a source or sink for atmospheric C. Agricultural soils can function as both a sink and source for atmospheric C. The soil humus pool associated with legume, grass covered Mollisols and the living biomass C pool found in tropical rain forests are two terrestrial ecosystems with the highest potential for C sequestration. The effects of conservation tillage on C balance within the entire soil profile, as compared to the surface 15 cm, have been questioned with arguments being raised that adoption of conservation tillage would simply result in a stratification of the SOM.