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Submitted to: Agrociencia
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/30/2012 Publication Date: 9/21/2012 Citation: Franzluebbers, A.J. 2012. Soil organic carbon dynamics under conservation agricultural systems. Agrociencia. 2012 Special Issue, p. 162-174. Interpretive Summary: Sustainability of agricultural systems relies on soil of high quality that is nurtured; a key indicator of soil quality is the level and distribution of soil organic carbon content. A scientist with USDA – Agricultural Research Service in Raleigh NC summarized recent literature on soil organic carbon sequestration in cropping systems of the southeastern USA for an invited speech at the 19th International Soil Tillage Research Organization conference in Montevideo, Uruguay. Soil quality can be enhanced with various conservation approaches that are based on three principles, namely minimizing soil disturbance, maximizing soil cover, and stimulating biological activity. This literature review helps frame future research to improve soil quality for millions of land owners in the southeastern USA and around the world. Technical Abstract: Soil organic carbon (SOC) is a key element in the valuation of natural resources and the evaluation of how management affects soil quality and ecosystem services derived from soil. This paper describes a summary of some recent research aimed at understanding how SOC contributes to (a) various soil properties and processes, (b) global cycling of carbon, and (c) support of various ecosystem services. Stratified SOC with depth under conservation agricultural approaches helps soil function to an optimum. Conservation management approaches focusing on minimizing soil disturbance, maximizing soil cover, and stimulating biological activity can be achieved with different cropping choices and production goals in different environments all around the world. In the southeastern USA, SOC sequestration was 0.30 + 0.05 Mg ha-1 yr-1 in no-tillage systems without cover crop and 0.55 + 0.06 Mg ha-1 yr-1 in no-tillage systems with cover crop, suggesting that greater C input with increasing cropping system complexity of no-tillage systems will be beneficial to SOC storage. The key to success for adoption of conservation agriculture will be to consider the agronomic, ecological, environmental, and economic constraints within a particular farm setting. On-going research continues to support the key contributions that enhanced SOC with conservation agricultural approaches can give to farmers and society. |
