Tillage-Induced CO2 Emissions and Carbon Sequestration: Effect of Secondary Tillage and Compaction

Abstract

Long-term data shows the effect of intensive tillage on soil carbon loss and suggests the need for alternative management strategies. Conservation agriculture with improved tillage methods can aid in carbon sequestration. This work demonstrated that secondary tillage methods decreased the CO2 loss immediately following the moldboard plow. Both the disk harrow and the field cultivator reduced the CO2 flux immediately following the moldboard plow operation by 40 to 50 %. Major soil reconsolidation with one pass of a road packer caused an abrupt decrease in the CO2 flux after primary tillage by moldboard plow, chisel plow, subsoiler, and paraplow. Further small decreases in CO2 fluxes were noted with four passes of the packer. The abrupt decreases in gas exchange were related to increases in soil bulk density following the compaction. These results demonstrate the importance of soil physical properties before and after tillage controlling gas fluxes and soil carbon loss.