242-12 Measuring Methane Emissions From Livestock Operations Using Open-Path Eddy Covariance.



Tuesday, October 18, 2011: 11:30 AM
Henry Gonzalez Convention Center, Room 207A, Concourse Level

Jay Ham, C-107 Plant Science Bldg, Colorado State University, Fort Collins, CO
Methane emissions from cattle feedlots in the High-Plains of the United States could represent a large component of agriculture's greenhouse gas inventory.   An eddy covariance system was used to quantify pen-scale CH4 fluxes from a commercial beef feedlot near Greeley, Colorado.   A  LI-7700 open‑path CH4 analyzer (Li-Cor Biosciences, Lincoln, NE, USA) was co-deployed with a sonic anemometer and open path CO2/H2O analyzer on a 10-m tower. Livestock weight, feed consumption, and pen surface conditions also were monitored in pens within the sampling footprint of the tower.  The performance of the LI-7700 CH4 instrument was strongly affected by dust on the lower mirror and a custom air-jet system was developed to improve performance. Large temporal-spatial variations in CH4 fluxes were apparent which required higher measurement heights and larger footprints. Methane fluxes from the cattle pens were compared to existing CH4 emissions models for beef cattle.
See more from this Division: S01 Soil Physics
See more from this Session: Symposium--Emission of Regulated and Greenhouse Gases: Measurement Technology, Monitoring and Policy: I