4.5
Measurement of CO2 carbon Isotope fluxes from conventional and no-till agricultural fields
G. B. Drewitt, University of Guelph, Guelph, ON, Canada; and J. Warland and C. Wagner-Riddle
This paper presents the initial results of a study of CO2 isotope flux measurements over tilled and no-till agricultural surfaces in Ontario, Canada. Measurements of CO2 flux were obtained using both eddy covariance and flux-gradient micrometeorological techniques. Additionally, the flux-gradient measurements distinguished between C12 and C13 - CO2 isotope concentrations and fluxes. The current crop rotation at the site (alternating between C3 and C4 species) combined with detailed soil sampling will allow us to resolve temporal changes in substrate used for microbial respiration. Furthermore, independent measurements of CO2 flux allow the calculation of turbulent transport coefficients which can be compared to those calculated using conventional wind-profile techniques. This paper will demonstrate some of these comparisons and show preliminary results of isotope flux measurements from conventionally-tilled and no-till plots during the spring thaw period. .
Session 4, Trace Gas Fluxes Including NH3, Aerosols, CH4, N2O etc
Tuesday, 23 May 2006, 3:45 PM-5:00 PM, Rousseau Suite
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