Compared with low TNS, the effect of N rate on the grain yield of rice was reduced significantly, and FNUE was also decreased to different extent under high INS.

• 与低土壤背景氮相比，在高土壤背景氮下水稻产量对氮肥的反应明显降低，氮肥利用率的各个指标均有不同程度下降。