The commercial and subsistence farms of the humid and sub-humid areas under irrigated and rainfed regions of Bangladesh were selected for data collection using a pretested questionnaire through individual household visits.

The extent of pollution by different system was calculated using IPCC Equation 10.23 and data were statistically analyzed using appropriate computer softwares. About 56.2 to 57.0% manure of large ruminants is kept in solid storage and 37.3 to 43.0% is used as burned fuel. Of the rest 4.80% is used in anaerobic digestion and 1.65% is lost as liquid slurry. The extent of manure used in solid storage was significantly (p<0.01) higher in commercial than subsistence farms irrespective of areas. The extent of burned fuel between the two farm types differed and it was significantly (p<0.05) higher in the commercial farm of sub-humid area but lower in humid and rainfed area. The methane emission factor of dairy & other cattle (bulls & growing animals), buffalo, small ruminants and poultry was calculated to be 6.77, 6.41, 5.42, 0.203 and 0.024 Kg CH4/head/year, respectively and the annual emission was estimated to be 62.98, 92.3, 7.97, 5.89 and 7.62 Gg methane, respectively.

Farmers` unawareness and their weak capacity and credit problem are the major constrains to improved manure management.