Ridge irrigation reduced greenhouse gas emission in double-cropping rice field

Abstract

ABSTRACT Ridge irrigation (RI) is a water-saving irrigation technique for paddy fields. To obtain a suitable mode of RI in increasing rice yield and reducing greenhouse gas (GHG) emissions from paddy fields, taking conventional irrigation (CI) as a control, the effects of RI with different ridge widths on rice yield, methane (CH4) and nitrous oxide (N2O) emissions, global warming potential (GWP) and GHG emission intensity (GHGI) in paddy fields of south China were investigated using the double-cropping rice field experiments. Compared with CI mode, RI with ridge width of 80 cm (RI80) increased the yields of double-cropping rice by 11.3–17.6% and decreased CH4 emissions from double-cropping rice fields by 45.6–70.3%. However, RI80 mode slightly increased N2O emissions from double-cropping rice fields. Compared with CI mode, RI80 mode decreased GWP and GHGI in double-cropping rice fields by 45.2–61.4% and 52.5–74.8%, respectively. Thus, the RI with ridge width of 80 cm was the optimal mode in increasing the yields of double-cropping rice and decreasing CH4 emission, GWP and GHGI in this study.