EMISSIONS OF TRACE GASES (CO2, CO, CH4, AND N2O) RESULTING FROM RICE STRAW BURNING

Emissions of trace gases (CO2, CO, CH4, N2O) resulting from rice straw burning were measured by using the open chamber method. The carbon co ntained in rice straw was mainly released to the atmosphere as CO2. Th e percentage of CO2-C emitted in total C in rice straw was in the rang e of 57-81%, followed by CO-C (5-9%). The percentages of CH4-C and N2O -N in total C and N in rice straw were in the range of 0.43-0.90 and 1 .16-1.50%, respectively. In the case of the rice straw which had been left in the field for a period of one month after harvest, emission of imperfect combustible gases such as CO and CH4 during burning increas ed slightly, while that of perfect combustible gas, CO2, was reduced. The amount of CH4 emission from rice straw burning was comparable to t hat from paddy fields.