不同施氮水平对良丰优339群体结构、产量和氮素利用率的影响

目的]研究不同施氮水平对杂交水稻品种良丰优339群体结构、产量及氮素利用率的影响,为良丰优339栽培调控和群体控制提供依据.方法]采用随机区组设计,设6个不同氮肥施用量处理（0、90、135、180、225、270kg/ha）,调查良丰优339茎蘖动态变化、产量及其结构因子和氮素利用率.结果]施氮量为90和135 kg/ha时对茎蘖动态控制较合理,氮肥偏生产力（NPFP）、氮素农学利用率（NAE）、氮素生理利用率（NPE）和氮素吸收利用率（NAE）均达到较高水平.在较低施氮水平下,有效穗数随施氮水平的提高而显著增加；在较高施氮水平下,结实率随着施氮水平提高而下降.结论]良丰优339在低氮条件下即可获得良好的群体结构、产量和较高的氮素利用率,其适宜施氮量为90～135 kg/ha.

Effects of different nitrogen fertilizer rates on population structure, grain yield and nitrogen use efficiency of Liangfengyou 339

Objective ]The effects of different nitrogen levels on population structure, grain yield and nitrogen use ef- ficiency of Liangfengyou 339 were studied to provide references for cultivation regulation and population control of the hy- brid rice variety Liangfengyou 339. Method]A randomized block was designed and six different nitrogen fertilizer treat- ments （0,90,135,180,225,270 kg/ha） were set to investigate tiller dynamics,yield and its structure factors, and nitro- gen utilization of Liangfengyou 339. Result]The tiller dynamics control were reasonable under 90 and 135 kg/ha with nitrogen partial factor productivity （ NPFP ）, nitrogen agronomy efficiency （NAE）, nitrogen physiologieal efficieney （NPE） and nitrogen absorption efficiency （NAE） at a higher level. At the lower nitrogen levels,the number of grains per panicle increased with increasing nitrogen levels. At higher nitrogen levels,grain weight and seed setting rates decreased with in- ereasing nitrogen levels. Conclusion ] Under low nitrogen eonditions, Liangfengyou 339 could get good population struc- ture, yield and high nitrogen use efficiency. N application 90-135 kg/ha was optimum fertilization application.