Author
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Reicosky, Donald |
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Submitted to: Carbon Sequestration In Soil An International Symposium
Publication Type: Abstract Only Publication Acceptance Date: 7/24/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Soil organic matter is the foundation of sustainable agriculture and is highly dependent on management decisions that influence the intensity of tillage and the amount and placement of residues. Large soil carbon reservoirs are of interest because soil can serve as a major source or sink for carbon dioxide, depending on the level of management. The objective of this work was to quantify the carbon dioxide loss following several method of tillage, both in the fall of 1992 and the spring of 1993 on a Barnes loam in West Central Minnesota. Carbon dioxide and water vapor fluxes were measured immediately after tillage using a large portable closed chamber designed for measuring crop canopy gas exchange. Tillage methods included moldboard plow, moldboard plow plus disk harrow, chisel plow and disk harrow only compared with a treatment not tilled. Moldboard plow was the most disruptive tillage treatment with most residue incorporation, greatest tsurface roughness,largest soil surface area and air spaces that all promoted carbon dioxide loss, compared to the plots not tilled. The relative flux differences based on tillage methods were similar in both spring and fall, only smaller magnitude in the spring. The seasonal difference was apparently due to cooler soil temperatures and wetter soil conditions that determined the flux and suggests fall tillage resulted in more carbon dioxide loss than spring tillage. Large differences in CO2 loss between conventional tillage and no-tillage and the smaller difference between spring tillage and fall tillage reflect the need for improved conservation tillage and residue management systems to enhance soil quality and promote carbon sequestration. |
