滇东低纬度高海拔区土壤化学性状对烟叶中硫、氯离子的影响

本文分析测定了低纬度高海拔的云南省曲靖市烟田土壤与烟叶的相关化学性状,通过分类树模型统计分析了烤烟中部叶片中硫、氯离子含量与土壤养分之间的关系。分析结果显示:(1)曲靖地区烟叶中硫的平均含量为0.26 mg/kg,含量范围在0.07~0.97 mg/kg,处于较适宜水平,但变异较大。有效硫、有效钙、海拔、速效磷、pH、有机质和速效钾均直接或间接影响烟叶中硫素含量,其中最主要因素是土壤有效硫含量。土壤有效硫含量≤35.53 mg/kg时,烟叶硫含量主要受土壤速效磷影响;土壤有效硫含量介于35.53~71.83 mg/kg时,土壤有效镁则成为影响烟叶硫含量的主要因素;土壤有效硫含量≥71.830mg/kg时,烟叶硫含量受土壤pH影响较大。(2)曲靖地区烟叶中氯离子平均含量为2.49g/kg,含量范围在0.20~34.7g/kg,处于较适宜水平,变异较大。土壤水溶性氯是影响烟叶氯离子含量的最主要因素,其含量分割点为4.97、28.48和51.93 mg/kg。除土壤水溶性氯外,土壤有效镁、速效磷和速效钙也在不同程度上影响烟叶氯含量。

Effects of soil chemical properties on S and Cl contents in flue-cured tobacco leaves in low-latitude and high-elevation area of east Yunnan

Chemical properties of soils and flue-cured tobacco leaves from low-latitude and high-elevation Qujing City of Yunnan Province were measured and Classification Tree Model was used to explore the relations between S and Cl-contents in tobacco leaves and soil various properties.The results showed that:(1) S content in tobacco leaves ranged from 0.07-0.97 mg/kg with a mean of 0.26mg/kg,which was more suitable level but with a great variation.Soil available S content was the uppermost factor affecting S content in tobacco leaves,soil available Ca,altitude,soil rapid available P,pH,organic matter and rapid available K were direct or indirect influential factors.S content in tobacco leaves was mainly affected by soil available P when soil S content was ≤35.53 mg/kg,was mainly affected by soil available Mg when soil S content ranged from 35.53 to 71.83 mg/k and then was mainly affected by soil pH when soil S content ≥71.830 mg/kg.(2) Cl-content in tobacco leaves ranged from 0.20-34.70 mg/kg with a mean of 2.49,with a great variation.Soil water-soluble Cl-content was the primary influential factor of Cl-content in tobacco leaves and the content cut-points were 4.97,28.48 and 51.93mg/kg respectively.Soil available Mg,rapid available P and Ca also affected Cl-content in tobacco leaves to various degrees.