TEMPORAL VARIATION OF METHANE EMISSION FROM RICE PADDY FIELDS OF GUJARAT

Methane flux studies from the flooded rice paddy fields of Kasindra vi llage in the Ahmedabad district of Gujarat during the monsoon season a nd the complete vegetation period (Aug.-Nov.) of 1992 were done using a static box technique. The rate of methane emission during this perio d varied between -0.36 and 27.43 mg m-2 h-1 and gave the integrated fl ux of 12.0+/-4.0 g m-2. The diurnal methane flux rates show large vari ation and are in the range 13.6-36.1 mg m-2 h-1 around flowering stage of paddy. The paddy fields when drained were a sink for methane. The total methane released from the Gujarat paddy is estimated to have a m ean value of around 0.03+/-0.01 Tg yr-1.