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【Objective】The present paper aimed to explore the feasibility of reducing the amount of nitrogen fertilizer and a reasonable nitrogen reduction model under late sowing wheat in the Jianghan Plain. 【Method】 Field experiments were conducted with Zhengmai 9023 under traditional and late sowing date with three nitrogen treatments differing in ratios of basal to topdressing. The changes in wheat yield and its constituent factors and nitrogen related indicators were compared across treatments. 【Result】（i） Under the same nitrogen application rate and base-topdressing ratio, grain yield, panicle number and 1000-grain weight were significantly reduced delayed the sowing date. Reduced total dry matter accumulation during flowering and maturity under late sowing was due to the decrease in dry matter accumulation in leaves and stem sheaths; The dry matter accumulation in spike did not show significant change. The changes in dry matter accumulation at maturity were related to leaves, stem+sheaths and grain husk+spike axis. Under the same nitrogen application rate and base-topdressing ratio, the nitrogen accumulation in wheat at flowering and maturity decreased as well; Nitrogen accumulation in flowering leaves of increased under late sowing, but nitrogen accumulation in stem+leaf sheath, ripe leaves and ripe grain husk+spike axis decreased. Under the same nitrogen application rate and base-topdressing ratio, the spike formation rate and nitrogen use efficiency were significantly reduced under late sowing.（ii）Under different nitrogen fertilization treatments and the same sowing date, nitrogen fertilization can be reduced from 180 to 150 kg/hm² under late sowing with insignificant change in yield decreased by 3.33 kg/hm²（M1） and 293.34 kg/hm²（M2） in 2019—2020; 158.67 kg/hm²（M1） and 13.50 kg/hm²（M2） in 2020—2021. The reduction was much lower than that of normal sowing, and the reason was that the number of spikes and grain number per spike were stable when the nitrogen application rate was reduced from 180 to 150 kg/hm², and the 1000-grain weight increased to some extent. Further reducing the amount of nitrogen applied, the yield change under the two sowing dates did not reach a significant level. Under the same base-topdressing ratio, reducing nitrogen application rate, the nitrogen accumulation in the stem+leaf sheath and spike at the flowering stage and grain husk+spike axis were significantly reduced, but dry matter accumulation did not change significantly. Under the same sowing date and base-topdressing ratio, reducing nitrogen application rate, spike formation rate increased significantly, M1 nitrogen utilization efficiency increased significantly, and M2 nitrogen utilization efficiency remained stable. 【Conclusion】Under the conditions of continuous optimization of nitrogen fertilizer management mode, the yield of late sowing wheat under nitrogen reduction treatment was not significantly reduced compared with normal nitrogen yield, but the spike formation rate and nitrogen use efficiency were significantly improved. After a delay of 20 days, the recommended nitrogen fertilizer management model is that the ratio of base to topdressing is m（base fertilizer）∶ m（top dressing before winter）∶ m（top dressing at jointing stage）=1∶1∶1, and the nitrogen application rate can be reduced from the normal nitrogen application rate to 150 kg/hm². [ABSTRACT FROM AUTHOR]

[Objective] This paper aims to provide optimal fertilization guidance for high-yield cultivation of P. frutescens and promotion of new P. frutescens varieties. [ Method] The effects of nitrogen, phosphorus and potassium fertilizers on the yield of two new P. frutescens varieties ( Qisu 2 and Qisu 3) were studied by ternary quadratic orthogonal rotation design. The regression equation and model analysis were constructed to optimize the high-yield fertilization mode. [ Result] N was the most important factor influencing the yield of P. frutescens. However, the two varieties varied in response to P and K fertilization. The regression models of nitrogen (x1) , phosphorus (x2) and potassium (x3) of the yield (Y) are Y = 2219.384 + 405.410x1, +304.926x2 - 156.723x12 -78.676x22 - 214. 479x1x2, and Y =2048.806 + 319.535x1, +54.722x3 -63. 102x12 - 113. 664x22 +76.017x32 -69.069x1x2, respectively. The best fertilization ratio of N, P and K fertilizer was (286.022 ±25.288),(139.059 ±20. 819),(180. 000 ± 35. 860) kg/hm2 , and (338. 180 ± 16.617) , (80. 923 ±21.314) , (203.529 ± 24. 278 ) kg/hm2, respectively. The yield of P. frutescens could reach 2250 kg/hm2. [ Conclusion ] Compound application of NPK fertilizers functioned significantly in enhancing P. frutescens yield. [ABSTRACT FROM AUTHOR]