The tradeoff between increasing productivity and environmental sustainability in super hybrid rice breeding

Super hybrid rice has significantly enhanced agricultural productivity in China, yet its environmental sustainability implications remain poorly understood. Using the food-carbon-nitrogen-energy-profit (FCNEP) framework, we evaluated five elite varieties (LYPJ, YLY1, YLY2, YLY900, XYL900) cultivated between 1999 and 2017. Field experiments were conducted from 2015 to 2017 across four provinces (Hubei, Hunan, Henan, and Jiangxi Province) in central China under four nitrogen treatments (0, 210, 300, 390 kg N/ha). Our findings reveal that while variety evolution boosted yields and reduced energy footprints (EFs), it also resulted in an increase in the nitrogen and carbon footprint (CF). Compared with LYPJ, newer varieties increased yields by 15.0–21.7% and net profits by 25.9–40.3%, while reducing energy footprints by 16.3–22.7%. However, nitrogen and carbon footprints rose by 8.0–34.5% and 31.0–76.6%, respectively. The composite sustainability score, derived from the FCNEP framework, indicated an initial improvement in sustainability during the early breeding stages of super hybrid rice. However, as breeding advanced, the sustainability score showed a subsequent decline. This study underscores the trade-off between enhancing productivity and maintaining environmental sustainability in superhybrid rice breeding. Future super hybrid rice breeding initiatives should prioritize balancing yield improvements with environmental considerations to promote sustainable agricultural development.