|Runion, G - AUBURN UNIVERSITY|
|Rogers Jr, Hugo|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 8, 1996
Publication Date: N/A
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. Our objective was to determine the effect of traffic-induced soil compaction and residue management history on the short-term tillage-induced CO2 flux from soils in nthe southeastern U.S. The study site was a Norfolk loamy sand cropped to a corn-soybean rotation for the last eight years. Experimental treatments included conventional tillage (disk harrow, chisel plow, field cultivator) (CT) and no-till (NT) as they affect residue management with and without traffic. A large spanner enabled tillage without wheel traffic on zero- trafficked plots. Short-term carbon dioxide flux was measured with a large portable chamber. Gas exchange measurements were made on both CT and NT at various times associated with tillage and irrigation operations on CT plots. Tillage-induced CO2 and H2O fluxes immediately after tillage were larger than corresponding fluxes from plots not tilled. Irrigation caused the CO2 fluxes to increase rapidly, suggesting soil fluxes were limited by lack of water. Tillage-induced CO2 fluxes were slightly larger from plots without traffic, however soil evaporation was not different. Interactions between tillage and residue management must be clearly understood before we can develop new management practices for enhanced soil carbon management in these sensitive soils.