Shifting from mid-season and double-season rice to ratoon rice improves the sustainability of rice production systems

The rising demand for food, climate change, energy shortages, and increasing production costs have exerted tremendous pressure on rice production in China. Exploring suitable rice cropping systems is crucial for promoting sustainable rice production. This study comprehensively compared three major rice cropping systems: middle-season rice (MR), ratoon rice (RR), and double-season rice (DR), focusing on grain yield, net ecosystem economic budget (NEEB), environmental benefits, and energy efficiency. The results indicated that the annual average yield of RR was 13.1 t ha⁻¹, which was 10.4%–12.4% lower than that of DR but 36.3%–36.6% higher than that of MR. The lower annual yield of RR relative to DR was mainly attributable to its lower ratoon season yield compared to the late rice yield in DR. Further increasing the ratoon season yield is key for RR to exceed the yield of DR. The global warming potential (GWP) of the three rice cropping systems ranged from 12334.4 to 18421.4 kg CO 2 -eq·ha⁻¹. Compared with DR, the GWP of RR and MR decreased by 21.7% and 33.0%, respectively. RR achieved the highest NEEB (13708.7 CNY·ha⁻¹), which was 25.0%-28.6% higher than DR and 18.2%-25.7% higher than MR, respectively. This superior performance was mainly attributed to RR's significantly high economic benefit, as well as its moderate ecological costs, by improving resource production efficiency. Furthermore, RR exhibited the highest energy use efficiency (3.4), exceeding MR by 6.3% and DR by 47.8%, primarily due to its superior energy output relative to MR (1926435 MJ ha⁻¹ vs 1411935 MJ ha⁻¹) and reduced energy inputs compared to DR (57140 MJ ha⁻¹ vs 95474 MJ ha⁻¹). These results demonstrate that RR represents a sustainable rice cropping system capable of balancing grain yield, NEEB, environmental benefits, and energy efficiency. This system is suitable for promotion in southern China where thermal resources are insufficient for DR but surplus for MR, as well as in regions transitioning from DR to MR, thereby enhancing the sustainability of rice production in China. Adopting high-ratooning varieties and optimizing cultivation techniques during the ratoon season may further enhance the overall performance of this system.