【Objective】The purpose of this study is to clarify the effects of the key period of reduced nitrogen application and appropriate reduced application rate on the yield and nitrogen absorption and utilization efficiency of late-maturing mid-japonica rice with different panicle types. 【Method】Using large panicle cultivar (Fengjing 3227, FJ3227), medium panicle cultivar (Huidao 5, HD5) and small panicle cultivar (Yangfujing 8, YFJ8) as materials, 12 nitrogen fertilizer treatments were designed, namely zero nitrogen application (0N), local conventional nitrogen application (CN, no nitrogen reduction, 300 kg/hm2), basal nitrogen fertilizer reduction by 10% and 20% (BN10, BN20), nitrogen reduction by 10% and 20% in tillering fertilizer(TN10, TN20), nitrogen reduction by 10% and 20% in flower-promoting fertilizer (SPN10, SPN20), nitrogen reduction by 10% and 20% in flower-preserving fertilizer (SNN10, SNN20) and average nitrogen reduction of 10% and 20% (AN10, AN20), to study the effects of different nitrogen reduction modes on yield and nitrogen absorption and utilization of medium-maturing japonica rice varieties differed in panicle type. 【Result】Under reduced nitrogen treatment, the overall yield of FJ3227, HD5 and YFJ8 decreased by 6.17%, 7.67% and 7.81%, respectively, with greater decrease in 20% nitrogen reduction. For FJ3227, HD5 and YFJ8 under the treatment of SPN10, AN10 and SSN10, the yield dropped by 0.17%, 0.79% and 0.23%, insignificantly lower than CN. Under the same nitrogen reduction model, the highest yield decline was observed in small panicle variety, followed by medium panicle type variety, and large panicle type variety. Nitrogen reduction reduced the number of effective panicles and the number of grains per panicle, but increased the seed setting rate and 1000-grain weight. As a result of nitrogen reduction, the number of effective panicles had the greatest promotion effect on the yield of the large panicle cultivar FJ3227, while the number of grains per panicle contributed the most to the yield of the medium panicle cultivar HD5 and the small panicle cultivar YFJ8. Nitrogen reduction treatment reduced the amount of nitrogen transportation and the amount of nitrogen accumulation. And the nitrogen reduction treatments reduced the nitrogen uptake at the jointing stage, heading stage and maturity stage. There were significant differences between treatments and varieties. Nitrogen reduction improved nitrogen fertilizer absorption and utilization and nitrogen partial productivity. Under the nitrogen reduction mode, the large panicle cultivar FJ3227, the medium panicle cultivar HD5, and the small panicle cultivar YFJ8 under the treatments of SPN10, AN10, and SSN10 have higher nitrogen use efficiency. 【Conclusion】The large panicle variety can reduce nitrogen by appropriate amount of fertilizer for promoting flowers, the small panicle variety can reduce nitrogen by medium amount of flower-preserving fertilizer, and the medium panicle variety can achieve nitrogen reduction without reducing yield and improve nitrogen absorption and utilization. Medium nitrogen reduction can adjust the growth characteristics of different panicle rice populations to achieve stable yield. Yet the excessive nitrogen reduction weakens its yield regulation capacity.
