|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|6458140||1420865||2017||9 صفحه PDF||سفارش دهید||دانلود رایگان|
- In the whole, the pasture emitted between 9 and 11Â g CH4Â mâ2 in 2013.
- Cattle emission represented 97% of the pasture emission.
- Eddy-covariance provided defensible in-situ estimations of methane enteric emissions.
- The soil of the pasture was a weak methane source.
The methane turbulent fluxes of an intensively grazed pasture were measured continuously from June 2012 to December 2013 at the Dorinne Terrestrial Observatory (DTO) in Belgium. During grazing periods, the fluxes were dominated by enteric fermentation and were found to be strongly related to cow stocking density. In 2013, total emission from the pasture was found between 9 and 11Â g CH4Â mâ2, 97% of which being emitted during grazing periods. Emission per LU (livestock unit) was estimated in a non-invasive way by integrating eddy covariance fluxes over large periods and by assuming a homogeneous average cattle disposition on the pasture.This estimate was compared to the one obtained during confinement periods, where cows were confined in a small part of the pasture. The emission per LU varied between 104 and 134Â g CH4 LUâ1Â dayâ1 (13 and 17Â g CH4 kg DMIâ1), depending on the dataset and the computation method used. Diel course was characterized by two emission peaks, one in the morning and a larger one in the afternoon. For rest periods (no cattle on the pasture), small emissions were observed (median and mean values of 0.5 and 1.5Â mg CH4 mâ2Â dayâ1, respectively).
Journal: Agricultural and Forest Meteorology - Volume 232, 15 January 2017, Pages 527-535