节水灌溉条件下水氮耦合对烤烟生长发育及生理性状的影响

以土壤水分下限和施氮量作为控制指标,研究水氮耦合对烤烟生长发育及光合蒸腾的影响.试验结果表明:相同土壤含水率情况下增大氮肥的使用量可以显著增大烤烟的叶面积指数,提高烟株叶面的光合活性,促进烤烟的生长;氮肥的用量还影响到烤烟对水分的吸收,当施氮量为67.5 kg/hm2并且伸根期、旺长期、成熟期的土壤水分控制下限(占田间持水量的百分数)分别为60%,80%和70%时,烤烟能够获得较好的品质和较高的产量.

Effect of coupling of water and nitrogen on growth, development and physiological indices of flue-cured tobacco under water saving irrigation conditions

Lysimeter experiments were performed to study the effect of the coupling of water and nitrogen on the growth,development and photosynthetic transpiration of flue-cured tobacco by controlling the lower limit of soil moisture and nitrogen application amount.The test results show that the increase of the dosage of nitrogen fertilizer can significantly increase the leaf area index of the flue-cured tobacco,raise the photosynthetic activity of the leaves and promote its growth under the same soil water content;the dosage of nitrogen fertilizer can also affect the water absorbing of the flue-cured tobacco.When the nitrogen application amount is 67.5 kg/hm2 and the lower limit(percentage of farmland water content) of the relative soil water content at the root extending stage,the vigorous growing stage and the maturing stage is 60%,80% and 70%,respectively,the higher yield and better quality of the flue-cured tobacco will be achieved.