烤烟套作绿肥对土壤养分和上部烟叶品质的影响

Influence of Intercropping Green Manure on Soils Nutrients and Quality of Upper Tobacco Leaves

为减少烟株后期对土壤氮的吸收,控制上部烟叶的烟碱含量,提高上部烟叶可用性,采用盆栽和大田试验方法,探索烟稻复种区植烟土壤质量优化的绿肥种植模式,分析该套作模式对植烟土壤供肥能力和上部烟叶烟碱等品质因子的影响。结果表明:套作高丹草能在短时间内积累较大的生物量;播种量为67.5kg/hm^2的高丹草能从烟田土壤中带走纯氮38.4kg/hm^2,烟田表层土壤全N、碱解N含量分别比对照降低6.9%和6.2%,套作后烟株吸收氮的总量减少10.76%,其中对土壤氮的吸收量减少12.59%;上部烟叶总N和烟碱含量分别比对照下降14.3%和12.6%。烤烟套作高丹草是减少后期烟草吸氮量、控制上部烟叶烟碱含量和提高上部烟叶可用性的有效途径。

In order to decrease soil nitrogen uptake of tobacco plants in later period, control nicotine content in upper tobacco leaves, and thus to enhance their usability, a pot experiment and a field experiment was conducted to explore the optimum cropping pattern of green manure under tobacco-rice rotation, so as to analyze the influence on fertilizer supplying ability for the tobacco and nicotine content in upper leaves. Results：A huger accumulation of biomass occurred in a short period through intercropping the sorghum hybrid sudangrass; The total and alkali-hydrolysable N contents in the surface tobacco soils where the seeding rate was 67. 5 kg/hm^2 were respectively 6. 9% and 6. 2% less than those of control group, indicating that the sorghum hybrid sudangrass could uptake 38. 4 kg/hme pure nitrogen out of tobacco fields; The total tobacco-absorbed nitrogen after intercropping decreased by 10.76%, where the tobacco-absorbed soil nitrogen reduced by 12.59%; The total N and nicotine content of upper leaves were 14.3% and 12. 6% less than those of the control group; Intercropping of tobacco and sorghum hybrid sudangrass was an efficient path for reducing nitrogen uptake in later period, controlling nicotine content in upper tobacco leaves and enhancing the usability of upper tobacco leaves.