Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/18/2003
Publication Date: 7/18/2003
Citation: REICOSKY, D.C. TILLAGE-INDUCED SOIL PROPERTIES AND CHAMBER EFFECTS ON GAS EXCHANGE. PROCEEDINGS OF INTERNATIONAL SOIL TILLAGE RESEARCH ORGANIZATION PROCEEDINGS. 2003. P. 117.
Technical Abstract: Agricultural ecosystems can play a significant role in the production and consumption of greenhouse gases, specifically carbon dioxide (CO2) from tillage. This work evaluated effects of tillage-induced changes in soil properties on CO2 and H2O loss as measured by a portable dynamic chamber. Information was collected on CO2 loss from the soil by measuring the concentration up and downwind without the chamber to characterize the plume of CO2 from a 5.5 m-wide plowed strip perpendicular to the prevailing wind. Downwind - upwind CO2 concentration differences were large immediately after tillage and decreased with time verifying the tillage-induced loss without the chamber. Short-term tillage-induced CO2 losses were measured with a large chamber using different air mixing rates and independently verified turbulent mixing pressure effects on CO2 losses. Fan number affected the CO2 and H2O flux from a freshly tilled surface. With only one fan operating (press. = -0.39 Pa), the fluxes were lower than with four fans (press. = -1.62 Pa) suggesting more negative dynamic pressure enhanced the flux. The results suggest plowing created higher soil air permeability more sensitive to pressure fluctuations resulting in higher gas exchange. The tillage-induced change in soil properties led to short-term CO2 losses that were higher than the undisturbed soil. The large differences in CO2 loss between moldboard plow and not-tilled treatments reflects the need for improved soil management and policies that favor less intensive conservation tillage to enable carbon (C) sequestration in agricultural production systems.