Effects of no-tillage practice for late-rice on rice yield and global warming potential in double-cropping rice systems

Double-cropping rice systems lead to intensive greenhouse gas emissions. No-tillage in late-rice season may be a viable practice to mitigate greenhouse gas emissions without compromising rice yield. A field experiment was conducted with two treatments: tillage for both early-and late-rice (T-T) and tillage for early-rice whereas no-tillage for late-rice (T-NT). The mitigation effect of no-tillage on CH 4 was mainly observed in the early vegetative stage. The difference of N 2 O fluxes between the treatments was mainly observed after fertilization. For the T-T and the T-NT in late-rice season, respectively, seasonal CH 4 emissions were 575.1 and 502.9 kg ha −1 , seasonal N 2 O emissions were 0.074 and 0.218 kg ha −1 , and rice yields were 5687 and 5169 kg ha −1 . CH 4 emission was responsible for more than 99% of the global warming potential (GWP). As a result, the T-NT decreased area-scaled GWP by 12.3%, but only decreased yield-scaled GWP by 3.0% due to yield decline by 9.1%. These results reveal that the T-NT is an effective practice in mitigating area-scaled GWP, the risk of yield loss, however, will undermine farmers’ willingness to adopt the practice.