Reducing methane emissions from rice fields

Emissions of methane from rice cultivation could be reduced dramatically by appropriate selection of species and reduction in rice paddy soil moisture.

Total anthropogenic sources of methane are estimated at about 275 Mt per year. However, as with natural sources, these estimates have large uncertainties.

Measurements of emissions from rice paddies show a strong dependence on season, rice type, soil conditioning and flooding control. Measurements of fluxes into the atmosphere from this source vary from a small sink to a source of more than 50 mg/sq m/day. Net global emissions from rice paddies are now estimate at 60 to 100 Mt/year, with China and India collectively contributing between 15 and 30% of this amount.