【摘要】 2007年在湖南浏阳烟草研究所采用大田随机区组试验,以烟草品种K326为材料,运用15N同位素示踪技术研究了多雨地区烤烟不同生育期对基肥和追肥中氮素的利用率。结果表明,烤烟在伸根期和旺长期以吸收肥料氮为主,成熟期以吸收土壤氮为主。在相同施氮量条件下随追肥比例增大,烤烟对基肥氮的吸收量减少,对追肥氮的吸收量增加,对基肥的利用率升高,对追肥的利用率降低,但各生育期烤烟对追肥的利用率都显著高于基肥。随追肥比例增大,烟叶采收结束后基肥氮在土壤中的残留量降低,追肥氮的残留量增加,但肥料氮的总残留量和损失量减少。因此,适当增大追肥比例可以提高多雨地区烤烟氮肥利用率。更多还原

【Abstract】 A field experiment was conducted using tobacco (Nicotiana tobacum L.) cultivar K326 grown in random block design with three replications in three treatments by 15N isotopes tracer in Liuyang institute of Hunan in 2007. The traits associated with nitrogen use efficiency were investigated during different growth stages of flue-cured tobacco. The results showed that tobacco plant mainly absorbed nitrogen from fertilizers in root elongation and vigorous growth stages and from soil in maturing stage. Nitrogen uptake reduced from base fertilizer, but increased from top dressing with the increase of top dressing under the same fertilizer application amount. At the same time, nitrogen use efficiency rose for base fertilizer, but declined for top dressing. The utilization of top dressing was significantly higher than that of base fertilizer in different treatments at different growth stages. After harvesting of tobacco leaves, nitrogen residue in base fertilizer was less than that in top dressing with the increase of top dressing ratio, but the total nitrogen residue and loss decreased. So enhancing properly the ratio of top dressing can improve ni-trogen use efficiency of flue-cured tobacco in rainy regions.更多还原