Effect of Aerated Irrigation and Straw Incorporation on Greenhouse Gas Emissions from Paddy Field during Soaking Period

Abstract

【Objective】 Soil stores more organic carbon than the atmosphere and biomass combined, and its change depends on a myriad of biotic and abiotic factors. This paper investigates the effect of aerated irrigation and straw incorporation on greenhouse emissions from paddy fields during soaking period. 【Method】 The experiments were carried out for rice grown in repacked soil pots. There were two irrigation treatments: conventional irrigation and aerated irrigation by mixing the irrigation water with micro-nano bubbles. For each irrigation, there were a straw incorporation treatment and a no-straw incorporation treatment. Emissions of CH4, N2O, CO2 from the soils in all pots were measured using the static closed chamber method. 【Result】 Straw incorporation combined with aerated irrigation increased the cumulative emissions of N2O, CH4 and CO2 by 30.67%, 167.08% and 76.95%, respectively, compared with the control without straw incorporation and aeration. Combination of straw incorporation and aerated irrigation slightly increased CO2 emission, but reduced N2O and CH4 emission by 10.11% and 32.63%, respectively, compared to straw incorporation without aeration. In terms of potential of global warming, conventional irrigation with and without aeration, and aerated irrigation combined with straw incorporation resulted in 7.53 g/m2, 14.14 g/m2 and 12.14 g/m2 of emission, respectively. 【Conclusion】 Straw incorporation under conventional irrigation during soaking period of the paddy field led to an increase in greenhouse gas emissions, and mixing the irrigation water with micro-nano bubbles can attenuate the emissions, especially N2O and CH4.

Keywords

• soaking period
• straw returning
• aerated irrigation
• greenhouse gas
• global warming potential (gwp)