| Burning of agricultural crop residues was a major source greenhouse gases. In this study,the proportion of crop straws (rice,wheat,maize,oil rape,cotton and soja) in Jiangsu used as household fuel and direct open burning in different periods (1990-1995,1996-2000,2001-2005 and 2006-2008) was estimated through questionnaire. The emission factors of CO2,CO,CH4and N2O from the above six types of crop straws were calculated by the simulated burning experiment. Thus the emission inventory of greenhouse gases from crop straws burning was established according to above the burning percentages and emission factors,ratios of dry residues to production and crop productions of different periods in Jiangsu province. Results indicated that emission factors of CO2,CO,CH4and N2O depended on crop straw type. The emission factors of CO2 and CH4 were higher for oil rape straw than the other straws,while the maize and the rice straw had the higher N2O and CO emission factor. Emission inventory of greenhouse gases from agricultural residues burning in Jiangsu province showed,the annual average global warming potential (GWP) of six tested crop straws were estimated to be 9.18 (rice straw),4.35 (wheat straw),2.55 (maize straw),1.63 (oil rape straw),0.55 (cotton straw) and 0.39 (soja straw) Tg CO2 equivalent,respectively. Among the four study periods,the annual average GWP had no obvious difference between the 1990-1995 and 2006-2008 periods,while the maximal annual average GWP(23.83 Tg CO2 equivalent) happened in the 1996-2000 period,and the minimum (20.30 Tg CO2 equivalent) in 1996-2000 period. |
