Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/29/2008
Publication Date: 10/5/2008
Citation: Smith, K.E., Runion, G.B., Rogers Jr, H.H., Prior, S.A., Torbert III, H.A. 2008. Greenhouse Gas Flux From Agricultural Soils: Impacts of 10 Years of Management and Elevated CO2 [abstract]. 2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM," October 5-9, 2008, Houston, TX.
Technical Abstract: An evaluation of the soil efflux of greenhouse gases (CO2, N2O, and CH4) from a conservation and conventional tillage system that has been under the influence of elevated atmospheric CO2 for the past 10 years will be presented. Fluxes of all greenhouse gases were significantly (p<0.05) greater under elevated vs. ambient CO2 regardless of tillage system effects. Carbon dioxide flux was generally greater in the conventional tillage system; however on two sampling dates following a large rain event in the summer months, flux from the conservation tillage system was slightly, but significantly, greater than in the conventional system. Methane fluxes were generally low with the conservation tillage system having lower fluxes than the conventional system. In addition, on several dates, the conservation system acted as a greater sink for CH4 than the conventional system; however the conventional system acted as a greater sink for CH4 on one date. Interestingly, the flux of N2O from the conventional system remained low throughout the study period; when looking only within the ambient levels of atmospheric CO2, the conservation system generally had lower fluxes of N2O. However, when looking across atmospheric CO2 level, a large flux of N2O was observed in the conservation system that had been exposed to elevated atmospheric CO2 for 10 years. The impacts of these systems and the fluxes of the measured greenhouse gases on the global warming potential of these two systems will be discussed. [GRACEnet Publication]