Can biochar amendment be an ecological engineering technology to depress N2O emission in rice paddies?-A cross site field experiment from South China

► Biochar amendment to seasonally flooded rice paddy fields could greatly depress N2O emission and increase N use efficiency while enhance soil fertility. ► Emission intensity of N2O in rice grain production could be greatly reduced while sustaining high yield, improving the managed wetland ecosystem services. ► As the above effects observed across the sites from South China, biochar amendment is recommended as an ecological engineering technology to mitigate N2O emission and sustain rice productivity in China.