Abstract:
The role of greenhouse gases (GHG) and their contribution to climate change has been subject of many studies in the
past two decades. In the agriculture sector ruminant livestock plays a dominant role in the emission of GHG through
their enteric fermentation. This study was conducted by using the ruminant livestock data for the past 15 years (1997
-2 0 1 1 ) and calculating CH4 and N20 using the guidelines according to Intergovernmental Panel for Climate Change O
(IPCC. 2006). Sri Lanka ruminant animal population diminished significantly during the past one and half decades.
During past 15 years, cattle and buffalo population (in cow equivalents) were diminished by 25.0% and 42.4%,
respectively. The annual CH4 emission from enteric fermentation by cattle was reduced from 62.2 to 47.5
Gigagrammes (Gg). whereas in buffalo from 39.8 to 22.9 Gg. CH4 emission from manure management of all species of
ruminant livestock decreased over the past 15 years. Emission from cattle and buffalo was decreased by 23.1% and
42.4% respectively. The overall reduction from cattle and buffalo was 30.6%. Annual direct emission of N20 from
cattle manure management reduced from 50.3 to 38.1 Gg, whereas in buffalo manure management the reduction was
15.1 to 8.6 Gg. The indirect emission of N20 from cattle manure management was reduced from 3.9 to 2.9 Gg. from
buffalo from 0.8 to 0.4Gg. In overall, reduction due to manure management from cattle and buffalo were 24.2% and
42.4%, respectively. With diminishing cattle and buffalo populations the total emission of CH4 and N20 were reduced
significantly.
