Maize and rice double cropping benefits carbon footprint and soil carbon budget in paddy field

•Double maize and Rice-maize cropping have higher carbon footprint and more soil carbon loss in comparison of traditional double rice cropping.•Maize-rice rotation significantly increased annual grain yield, showed comparable total CO2 eq emissions and lower carbon footprint.•Maize-rice rotation could be the better alternative cropping system in double rice paddy in subtropical region in China. Cropping systems in double rice paddies in subtropical region of China are under conversion to a rice-upland rotation or upland crops production driven by economic benefits and social conditions. However, limited studies have been completed to evaluate the productivity and environmental consequences following the introduction of maize to paddies in this area. Four cropping systems were practiced in our experimental field plots: traditional double rice (R-R), maize-rice rotation (M–R), rice-maize rotation (R-M) and double maize cropping (M-M). The two-year study showed that conversion to maize-related cropping patterns led to a substantial change in GHG emissions, carbon footprint and net soil carbon budget (NSCB) on a short-term timescale. Although the M-M treatment resulted in a 13.5% higher annual grain yield than the R-R treatment, it showed a tremendous increase in total CO2 eq emissions of 47.7% and higher soil carbon loss, thus, it had a higher carbon footprint than the R-R treatment by 30.7% (p