3-YEAR MEASUREMENT OF METHANE EMISSION FROM AN INDONESIAN PADDY FIELD

Yearly and seasonal (rainy and dry seasons) variations of CH4 emission from a Sumatra paddy field were measured for 3 years. The mean CH4 em ission rates during the growth period were in the range of 16.0-26.1 m g CH4 m(-2) h(-1) for the chemical fertilizer plots and 23.3-34.9 mg C H4 m(-2) h(-1) for the plots with rice straw application, respectively . The increase in the amounts of CH4 emission by rice straw applicatio n were from 1.3 to 1.6 times. There was no significant difference in t he mean CH4 emission rates between rainy and dry seasons. Total amount s of CH4 emitted during the period of rice growth were in the ranges o f 29.5-48.2 and 43.0-64.6 g CH4 m(-2) for the plots applied with chemi cal fertilizer and those with rice straw application, respectively. Ne arly the same, amounts of CH4 were emitted in the first and second hal f of the growth period, irrespective of rice straw application.