Wednesday, November 15, 2006

Temporal Dynamics of Greenhouse Gas Fluxes Linked to Soil Biophysical Processes and Management Practices.

Claudia Wagner-Riddle, Jon Warland, Gordon Drewitt, Adriana Furon, Kari Dunfield, Jillian Smith, Paul Voroney, Ravindra Ramnarine, and Jenna Rapai. University of Guelph, Dept. of Land Resource Science, Guelph, ON N1G 2W1, Canada

Studies of tillage effects on N2O emissions have been inconclusive due to the high temporal variability in emissions and the complexity of controlling factors. Increase in carbon and moisture levels in no-tillage (NT) soils can lead to higher N2O emissions during the growing season, however, in cold climates improved soil structure in no-till can lead to reduced N2O during spring-thaw compared to conventional tillage (CT). The temporal dynamics of CO2 (12C and 13C - CO2 isotopes) and N2O fluxes of NT and CT plots, linked to soil chemical, physical, and microbial community structure measurements are the focus of a project initiated in 2005. This paper presents the initial results of flux measurements using micrometeorological techniques, sampling to determine carbon content and δ13C of soil and plant pools, and genetic diversity of the nitrifier and denitrifier communities.

Handout (.pdf format, 650.0 kb)