Carbon Balance of Switchgrass Using Eddy Covariance Measurements.

In the last couple of years, Switchgrass (Panicum virgatum L.) has gained importance as a feedstock for biofuel. A thorough assessment of greenhouse gas (GHG) fluxes associated with feedstock production is needed to compare different types of fuels. To improve life cycle analysis of Switchgrass direct GHG flux measurements are needed under various climatic conditions. In December 2011 we started eddy covariance measurements of CO₂ and latent heat fluxes over a Switchgrass field in Southern Ontario. Switchgrass was established six years ago on this 60-ha commercial field. Therefore, the flux results are expected to be representative for commercial Switchgrass farming under the climatic conditions of Southern Ontario. The measurements will be running for at least 2 years and will give deeper insight into the carbon cycle of Switchgrass in a cold climate. The first results from winter, spring and summer 2012 will be presented. Energy Budget Closure at this site for summer 2012 is around 80%. Daily mean CO₂ fluxes as low as -10 umol/(m*s) have been observed in the summer so far.