Reducing greenhouse gas emission by alternating the upland crop rotation in the Mekong Delta, Vietnam

Agricultural production is one of the main sources of anthropogenic greenhouse gas (GHG) emissions, contributing 50% and 60% of CH4 and N2O emissions, respectively. This study evaluated the rice yield and components, the CH4 and N2O emissions and the global warming potential between the triple rice (R-R-R) and sesame-rice rotation (S-R-R) systems in Can Tho city, Vietnam. The experiments were conducted in three cropping seasons: spring-summer 2016, summer-autumn 2016, and winter-spring 2016-2017. The results showed that there was no significant difference in the yield components and grain yield between the triple rice and sesame-rice rotation systems. The application of a sesame rotation in rice-based system could reduce the CH4 and N2O emission by 30.5% and 18.7%, respectively. The global warming potential in the S-R-R rotation was 9 860 kg CO2e/ha, significantly lower than the R-R-R rotation (12 410 kg CO2e/ha) by 20.6%. These results show that the S-R-R rotation has the potential to mitigate the GHG emissions, especially CH4, which contributes a large amount of emissions in the rice cultivation.