Evaluating the sustainability potential of perennial rice in southeastern China by comparing yield, environmental impacts and economic benefits

The perennial rice (PR) cultivation system is an ecologically sustainable and environmentally-friendly approach that offers enhanced resource efficiency, thereby presenting the potential to supplant traditional double-cropping rice (DR) and ratoon rice (RR) systems in China's southeastern region. However, there is still a dearth of comprehensive studies examining the yield, carbon and nitrogen footprints, economic benefits, and carbon budget balance associated with PR. This study systematically compares the performance of PR, DR, and RR cultivation systems in terms of yield, direct greenhouse gas (GHG) emissions, carbon and nitrogen footprint, net ecological-economic benefits (NEEB), and net ecosystem carbon balance (NECB), based on field trials conducted from 2022 to 2024. The results from three years of research indicated that the annual yield of PR was comparable to that of DR and RR. However, PR exhibited a significant reduction in direct GHG emissions, which were 21.7 %–25.91 % lower than those of DR. Similarly, the carbon and nitrogen footprint of PR were reduced by 19.34 %–25.87 % and 7.12 %–9.17 %, respectively, while the carbon and nitrogen footprint per unit yield decreased by 16.76 %–28.02 % and 7.29 %–9.17 %. Additionally, the annual energy input of PR was reduced by 26.74 % and 2.10 % compared to DR and RR. In terms of economic benefits, the NEEB of PR was 83.24 % higher than that of DR and 10.85 % greater than that of RR. Furthermore, NECB of PR was significantly higher than that of DR and RR, with increases ranging from 15.77 % to 37.87 % and from 15.30 % to 43.45 %, respectively. These advantages were primarily attributed to reductions in methane emissions (CH₄), ammonia volatilization (NH₃), and lower indirect agricultural inputs. The findings suggest that despite the comparable yield of PR to that of DR and RR over the three-year trial, its significant advantages in terms of carbon and nitrogen footprints, energy input, and economic benefits indicate that PR represents a highly promising sustainable agricultural model for the southeastern region of China. It has the potential to maintain high productivity while reducing resource inputs and environmental pressures. In the future, further optimization of PR breeding and cultivation management may result in higher and more stable yields while maintaining low energy inputs and environmental costs.