COVER CROP AND SOIL QUALITY INTERACTIONS IN AGROECOSYSTEMS

Authors: Reicosky, Donald; Forcella, Frank

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The increase in the carbon dioxide in the atmosphere has attracted interest due to the concerns about potential global warming and the prospects of using soil as a sink for carbon released by human activity. The cumulative effect of tillage and many cropping rotations has been an undesirable change in soil physical, chemical and biological properties, primarily the decrease of soil carbon. Cover crops can play an important role in enhancing and maintaining soil quality at the ecosystem level by increasing soil carbon. Cover crops are a main contributor to maintaining resource quality when environmental issues are considered in agricultural production systems by maintaining soil, water and air quality at the individual field level as well as at the ecosystem level. Progress is being made in developing soil conservation practices that include cover crops that can further enhance soil carbon management. These results are significant to farmers and policy makers in that cover crops result in short-term carbon sequestration. Information will be beneficial to farmers because they can develop and utilize new management techniques for enhancing soil carbon by increasing the quantity and quality of carbon residues in cover crops and by changing the type and intensity of tillage. The conservation of our soil resources and the sustainability of our cropping systems can be enhanced through better soil carbon management. Agriculture's contribution to controlling the increased carbon dioxide in the atmosphere to minimize potential global warming requires that we use cover crops to manage soil carbon and utilize soil as a sink for carbon released by other human activity.

Technical Abstract: Management of crop residues and soil organic matter is of primary importance in maintaining soil fertility and productivity and for minimizing agricultural impact on environmental change. Cover crops can play an important role in meeting the objectives of sustainable agriculture, preserving productivity of soil resources, and maintaining environmental quality. Understanding effects of cover crops on soil properties, hydrological processes, and water and air quality is critical to continued production of food and fiber. This work addresses interactions of cover crops and soil quality as related to watershed hydrology, soil-water relationships, and soil physical properties at the ecosystem level. Cover crops have protective value, whereby vegetation and residue cover the soil and control erosion by providing resistance to soil particle detachment and transport by wind and water. Decomposing plant materials from cover crops also give rise to other functions that contribute to the maintenance of dynamic soil organic matter levels. Higher soil organic matter is related to soil erosion control because of increased infiltration and rainfall retention. Cover crops help maintain soil, water and air quality at the individual field level as well as at the ecosystem level. Sustainable agriculture is dependent on maintaining soil organic carbon in proper balance within the natural carbon cycle. Carbon input from cover crops and crop stover can play a substantial role in maintaining the soil resource for long-term production. The importance of cover crops in our management decisions and the role they play in maintaining environmental quality affects all major resources required for food production, especially soil quality.