The carbon (C) and nitrogen (N) metabolism directly affects chemical component and quality of Tobacco,and the soil carbon-nitrogen ratio (C/N) is the major factor responsible for the C and N metabolism of tobacco and its chemical composition.In this study,six C/N ratio treatments were set:0,6,20,40,60,90,the C/N ratio in all of these treatments were adjusted by the maize straw and sesame manure,with the objectives to explore the effect of C/N ratio on the agronomic traits and chemical component of tobacco by the pot experiment.The results were showed that the dry matter of tobacco roots,stem,and leaves were decreased under the treatments with the C/N ratios of 90,0,and 6.While under the treatments with C/N of 20 and 40,the tobacco leaf area was increased,approximately to 600 m2,resulting in increase of dry matter of tobacco roots,stems,and leaves in the relevant treatments (i.e.the dry matter of tobacco leaf was around 80 ~ 95 g· plant-1).For chemical component,un der C/N of 90,the N and phosphorus absorption of tobacco leaf was reduced,and the content of nicotine in the tobacco leaf at middle and bottom part decreased,while the potassium (K) content increased to the maximum level of 31.3 g· kg-1.The content of total sugar and reducing sugar of tobacco increased as C/N ratio increased.In conclusion,C/N ratio of 20 to 40 is favorable for tobacco growth and chemical composition.%采用盆栽方法,利用玉米秸秆和芝麻饼肥进行碳氮比的调节,共设置6个碳氮比水平(0,6,20,40,60,90),研究了不同碳氮比的有机物料对烤烟生长发育和化学成分特征的影响.结果表明,土壤碳氮比过高(C/N=90)或过低(C/N=0,6)均抑制烤烟农艺性状的发育,进而减少了根茎叶干物质累积;而土壤碳氮比在20~40时,则可以提高烟叶的叶面积(圆顶期达到600m2左右),有利于根茎叶干物质的累积(圆顶期叶片干重达到80~95g·株-1).碳氮比过高的处理(C/N=90)阻碍了烤烟叶片对氮、磷的吸收,降低了中下部烟叶烟碱的含量,但有利于烤烟中下部叶片钾的吸收和累积,最高达31.3 g·kg-1,同时提高了钾氯比.烤烟的总糖和还原糖含量基本随土壤碳氮比增加而增加,淀粉含量则呈现相反趋势.综合来看,土壤碳氮比在20~40时,更有利于烤烟农艺性状的发育,同时促进碳氮代谢的协调发展,有利于烤烟主要化学组分的合理分配.
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