基肥一次性供氮对烤烟氮素吸收利用的影响

摘要

为探讨基肥一次性供氮条件下的烤烟优化施氮问题,采用大田小区试验,探讨了基肥一次性供氮条件下不同化学施氮量对烤烟氮素吸收利用的影响.结果表明:1)在基肥一次性供氮条件下,经过一个生长季之后基施的化学氮基本消耗殆尽,48～ 168 kg·hm-2范围内增施化学氮没有促进植烟土壤氮素积累的作用；2)与不施化学氮处理比,48、108、168 kg·hm-2的不同化学氮处理均显著促进了烤烟的氮素吸收(P＜0.01),烤烟产量分别为不施化学氮处理的170%、152%和149%,起到有效促进烤烟生长、提高烤烟产量的显著作用(P＜0.0l)；3)在48～168 kg·hm-2范围内不同化学氮处理间烤烟氮吸收量差异不显著(P＞0.05),随着化学氮量增加,烤烟产量、产值呈下降趋势,烤烟氮肥利用率和氮素农学利用率直线下降；4)基肥一次性供氮条件下增施化学氮有降低烤烟总糖、还原糖含量和提高烟碱含量的作用,但试验供氮范围内烤烟糖碱比仍在合理范围.从基肥一次性供氮的试验结果看,低化学氮处理(48 kg· hm-2)能有效地满足烤烟氮养分需求,显著提高烤烟化学氮的利用效率.%To study the effects of nitrogen fertilizer applied as only basal on N absorption and utilization of flue-cured tobacco,a field experiment was conducted using flue-cured tobacco, Nicotiana tobacum L. , cultivar Yue 97 grown in a completely randomized block design at Nanxiong Tobacco Science Institute of Guangdong in 2009. The results showed that;1) Under nitrogen fertilizer applied as only basal,the soil supplying nitrogen capacity at late growth period of tobacco was not promoted evidently by the increasing of nitrogen application in the range of 48 -168 kg · hm-2.2) Nitrogen uptake by tobacco could be pro-moted significantly from artificial nitrogen application, the yield of tobacco applied with artificial nitrogen fertilizer at 48,108,168 kg · hm-2 was equivalent to 170% ,152% and 149% of the treatment without artificial nitrogen application, respectively, and artificial nitrogen application could increased growth and yield of tobacco. 3 ) Nitrogen uptake by tobacco could not be promoted evidently by the increase of artificial nitrogen application in the range of 48 -168 kg · hm-2(P ＞0. 05) ,while there was the decline of their nitrogen use efficiency, nitrogen agronomic efficiency, yield and output value. 4) Tobacco total sugar and reducing sugar decreased evidently with the increased of total nicotine from adding artificial nitrogen fertilizer. However, the sensory quality of flue-cured tobacco was not be affected significantly by the enrichment of artificial nitrogen. The nitrogen fertilizer applied as only basal by artificial nitrogen 48 kg · hm -2 can meet the need of nitrogen nutrition of tobacco and enhance significantly its nitrogen use efficiency and nitrogen agronomic efficiency.