Preprints
https://doi.org/10.5194/bgd-9-14407-2012
https://doi.org/10.5194/bgd-9-14407-2012
17 Oct 2012
 | 17 Oct 2012
Status: this preprint was under review for the journal BG. A revision for further review has not been submitted.

Methane emission measurements in a cattle grazed pasture: a comparison of four methods

T. Tallec, K. Klumpp, A. Hensen, Y. Rochette, and J.-F. Soussana

Abstract. Methane (CH4) is considered to be the second main contributor to the global greenhouse gas effect, with major CH4 emissions originating from livestock. Accurate measurements from ruminating herds are required to improve emission coefficients used in national emission inventories, and to evaluate mitigation strategies. Previous measurements of enteric methane emissions from domestic animals have been carried out in artificial conditions such as laboratory chambers, or by fitting individual animals with capillary tubes and using SF6 as a tracer. Here we evaluated the reliability of eddy covariance technique (EC), already used for CO2 fluxes, for continuous CH4 measurements over a grazed field plot. Analyzer accuracy and reliability of eddy covariance technique were tested against field scale measurements with the SF6 tracer technique, Gaussian plume model and emission factors (i.e. IPCC). Results indicate a better agreement between EC and SF6 method when grazing heifers were parked close to the EC setup. However, a systematic underestimation of EC data appeared and even more when the distance between the source (ruminating heifers) and EC setup (mast) was increased. A two-dimensional footprint density function allowed to correct for the dilution effect on measured CH4 and led to a good agreement with results based on the SF6 technique (on average 231 and 252 g CH4 ha−1 over the grazing experiment, respectively). Estimations of the CH4 budgets for the whole grazing season were in line with estimates (i.e. emission factor coefficients) based on feed intake and animal live weight as well as SF6 technique. IPCC method Tier 2, however, led to an overestimation of CH4 fluxes on our site.

T. Tallec, K. Klumpp, A. Hensen, Y. Rochette, and J.-F. Soussana
 
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
T. Tallec, K. Klumpp, A. Hensen, Y. Rochette, and J.-F. Soussana
T. Tallec, K. Klumpp, A. Hensen, Y. Rochette, and J.-F. Soussana

Viewed

Total article views: 1,434 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
862 510 62 1,434 44 50
  • HTML: 862
  • PDF: 510
  • XML: 62
  • Total: 1,434
  • BibTeX: 44
  • EndNote: 50
Views and downloads (calculated since 01 Feb 2013)
Cumulative views and downloads (calculated since 01 Feb 2013)

Cited

Saved

Latest update: 19 Apr 2024
Download
Altmetrics