Abstract:Rice cultivation is an important source of CH4 and N2O. Greenhouse gas emission reduction in rice field has always been a hot topic in agro-ecological research. In this study, under two conditions of open field cultivation and insect-proof net cultivation, the effects of rice-duck (RD) farming and wheat straw returning on greenhouse gas emission and related soil physiochemical properties of paddy field were investigated by a split-zone experiment. The treatments included conventional rice farming with inorganic nitrogen fertilization (CR+IN), RD farming with inorganic nitrogen fertilization (RD+IN), conventional rice farming with wheat straw returning (CR+WS) and RD farming with wheat straw returning (RD+WS), and the emissions of CH4 and N2O, methanogenic potential and CH4oxidation potential, soil denitrifying enzyme activity, and global warming potential of paddy fields were determined. The results showed that straw returning increased methanogenic potential and CH4 emission from paddy field, but decreased soil denitrifying enzyme activity, soil redox potential and N2O emission. As a whole, the global warming potential of straw returning increased by 96.89%-123.02%. In RD farming, due to the uninterrupted activities of ducks, redox potential of paddy soil was increased, CH4 production potential and CH4 emission of paddy field was reduced, global warming potential decreased by 8.72%-14.18% compared with conventional rice without ducks. The insect-proof net cultivation significantly increased redox potential of paddy soil, decreased methanogenic potential and soil denitrifying enzyme activity of paddy field, reduced the emissions of CH4 and N2O from paddy field and the global warming potential by 6.35%-13.1%. On the whole, CH4 oxidation potential of paddy soil was 9.46-12.20 times as high as methanogenic potential. RD farming and straw returning could increase rice yield. However, insect-proof net cultivation reduced rice yield by 1.19%-5.48%. In a word, RD farming could not only slow down the global warming potential, but also increase rice yield combined with straw returning, which had extensive application value.