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MEKARN Workshop 2009: Livestock, Climate Change and the Environment |
An environmental assessment of rice straw burning practice in the Mekong Delta has been carried out from 2003-2004 on 252 households survey in O Mon district, Can Tho City and Cai Lay district, Tien Giang Province. Sample collecting and analyzing in the laboratory to measure the content of C, S, N, P and K in rice straw and ash after burning and estimate the concentration of CO, CO2, NO, NOx and SO2 gas in rice straw burning smoke.
Burning rice straw (quantity) in Summer-Autumn 2003 was 91.6% and in Autumn-Winter was 63.4% at two study sites. In the Winter-Spring 2004, 100% farmers applied burning straw in O Mon and Cai Lay districts; The amount of rice straw burned was 100% in On Mon and 97.9% in Cai Lay districts. In average, it was 87.5% burned straw in estimation for the year 2003-2004.
From 5 gases measured (CO, CO2, NO, NOx, SO2), there are CO, CO2 and NO were found significantly and all exceed the standard of air pollution. In mass calculation, burn one tone rice straw lost 91.3% carbon (C) which equivalent to 291.2Kg C and may released 1,067.6 kg CO2 and 12.6 kg NO.
Taking an estimation of grain : straw = 1 and total rice grain productivity at the Mekong Delta was 25M tones and 87% rice straw burned, that burning rice straw practice released 23.2M tones CO and CO2 yearly!