Abstract:

Effects of nitrogen application regimes, based on the proportion of base-tillering fertilizer to panicle fertilizer and leaf age of panicle fertilizer supply, were studied on yield，nitrogen use efficiency and quality in supper japonica hybrid rice, cv. Changyou 1, under the high grain yield at 225 kg ha^-1 of N condition during a whole growth stage. The result indicated that the yield was influenced significantly by nitrogen application regimes. The regime for highest yield was that the ratio of base-tillering fertilizer to panicle fertilizer was 58.34:41.66, and the split panicle fertilizers were equally applicated at 4th and 2nd leaf age from top. There were highly significantly positive correlations between yield and total N uptake，agronomic N use efficiency, apparent N recovery efficiency，physiological N use efficiency, and significantly quadratic relationships between yield and N kg 100 kg^-1 grain yield, N harvest index. With the decreasing of N rate of panicle fertilizer，head milled rice, protein content，chalky ratio and chalkiness were decreased; gel consistency and amylose content increased gradually. With postponing the time of N-applying leaf age, head milled rice and protein content were raised，and amylose content dropped. The gel consistency and apparent features were varied by different application proportions. On the whole，the proportion of N-application at 6:4 and the top dressing of panicle N-fertilizers with equal amount at 4th and 2nd leaf age from top might realize the coordination of supper high-yield，good quality and high N use efficiency.

Key words: Super japonica hybrid rice, Nitrogen application, Yield, Quality, Nitrogen use efficiency