氮肥运筹对鄂南直播稻生长、产量及氮素吸收的影响

采用田间试验,研究了氮肥运筹对直播稻生长、产量及氮素吸收的影响,以期为氮肥的合理施用提供依据。结果表明,施用氮肥增产效果明显,与不施氮处理(T1)相比,平均增产1 010 kg/hm2,增产率17.0%,其中氮肥分3次施用的处理增产效果最佳,增产1 468 kg/hm2,增产率24.7%;氮肥的施用能够显著增加水稻吸氮量,各施氮处理在苗期、分蘖末期、齐穗期和收获期吸氮量与T1相比分别增加34%、125%、80%和39%;氮肥的合理运筹显著提高了氮肥吸收利用率,与氮肥全部作基肥处理相比,氮肥50%作基肥、30%作苗肥、20%作分蘖肥(T4)和氮肥35%作基肥、30%作苗肥、15%作分蘖肥、20%作穗肥(T5)分别提高了22个和28个百分点。综合分析认为,本试验条件下,T4处理的氮肥运筹效果最好,可以在鄂南直播稻生产上推广应用。

Effect of Nitrogen Application Regime on the Growth,Yield and Nitrogen uptake of Direct-seeding Rice in the South of Hubei Province

A field experiment was conducted in Chibi city, to study the effects of nitrogen （N） application regime on the growth, yield and N uptake of direct-seeding rice in the current production conditions in order to provide evidence for scientific application of N fertilizer. The results showed that the application of N increased the yield significantly by 1 010 kg/hm2 and 17.0% compared to that of the treatment of no N （T1）. And the increase of yield of the treatment of total N splited 3 times was the most, increased by 1 468 kg/hm2 and 24.7%. The N uptake of the treatment of N application in the stage of seeding, tillering, full heading and harvest were in- creased by 34%, 125%, 80% and 39% compared to that of the T1 treatment. Reasonable application of N improved the nitrogen fer- tilizer use utilization significantly. The N recovery efficiency of the treatment of split application （T4 and T5） were increased by 22 and 28 percentage point compared to that of the treatment of total N as basal fertilizer. Under the trial condition, the treatment of 50% of total N as basal fertilizer, 30% as seedling fertilizer and 20% as tillering fertilizer was the best, and it is worthy of extending to application.