基于能量效率与碳效率的长江中游不同水旱轮作系统可持续性分析

Sustainability analysis of different upland-paddy rotation systems in the middle reaches of the Yangtze River based on energy efficiency and carbon efficiency

长江中游地区是我国典型水旱轮作区,合理评价不同水旱轮作模式的生态经济效益对推动该区稻田可持续生产具有重要意义。本研究选取玉米-晚稻(MR)、油菜-中稻(RR)和小麦-中稻(WR)3种水旱轮作模式,对比其在秸秆还田(S+)与秸秆不还田(S–)处理下的作物产量、能量效率和碳效率等方面的差异。结果表明:(1)MR模式作物产量较RR和WR模式显著高22.25%和14.81%。秸秆还田显著提高MR、RR和WR模式作物产量7.12%、6.54%和6.43%。(2)MR模式光能利用率和产投比均显著高于RR与WR模式,耗能强度显著低于RR和WR模式。秸秆还田显著提高MR、WR模式光能利用率和RR、WR模式耗能强度,显著降低MR、RR和WR模式产投比。(3)MR模式碳生产效率和碳生态效率显著高于RR和WR模式。秸秆还田显著提高了MR、RR和WR模式碳生产效率和碳生态效率。(4)MR模式碳足迹显著低于RR和WR模式。秸秆还田显著降低了MR、RR和WR模式碳足迹。综上,与油菜-中稻和小麦-中稻模式相比,玉米-晚稻模式具有较高的作物产量、能量效率、碳效率和较低的碳足迹;秸秆还田利于提高作物产量,同时提高了各模式能量效率和碳效率,降低了碳足迹。可见,玉米-晚稻水旱轮作配合秸秆还田具有较好的生态经济效益,可作为长江中游水旱轮作区一种可持续生产技术。

Upland-paddy rotations play a vital role in the middle Yangtze River region of China.It is crucial to rationally evaluate the environmental and economic benefits of different crop rotation patterns for sustainable crop production.This study investigated three upland-paddy rotations:maize-rice(MR),rapeseed-rice(RR),and wheat-rice(WR),to assess crop yields,energy efficiency,and carbon efficiency under two treatments:straw return(S+)and straw clearance(S–).The results revealed that the MR rotation had a significant increase in yield,with 22.25%and 14.81%higher yields compared to RR and WR,respectively.Incor-porating straw return led to a significant improvement in crop yield for MR,RR,and WR,with increases of 7.12%,6.54%,and 6.43%,respectively.Furthermore,the MR pattern exhibited significantly higher radiation energy utilization efficiency(RUE)and output/input ratio(O/I)compared to RR and WR,with significantly lower energy consumption intensity(EI).Straw return im-proved RUE for MR and WR,increased EI for RR and WR,and decreased O/I across all patterns.Additionally,carbon production efficiency and carbon ecological efficiency were significantly higher for MR compared to RR and WR.Straw return significantly improved efficiencies in all patterns.Moreover,the carbon footprint(CF)of MR was significantly lower than that of RR and WR,and straw return also reduced CF significantly in all patterns.Overall,the study results demonstrate that the MR rotation has higher crop yield,energy efficiency,carbon efficiency,and lower CF.Additionally,straw return can increase crop yield,improve energy efficiency and carbon efficiency,and reduce CF in all patterns.In conclusion,the maize-rice rotation with straw return can be considered a sustainable and beneficial technique for rice production in the middle Yangtze River region.