砷对烤烟生长发育及其产量和品质的影响

为了考察砷毒害对烤烟生产的影响,采用盆栽试验,研究了砷与烤烟生长发育、产量和品质的关系。结果表明,砷抑制了烤烟的生长发育,导致其生育期延迟,叶片数和叶面积减少,株高和产量降低。同时,砷造成了烤烟产值、均价和上中等烟比例降低,使其经济性状变差,总糖、还原糖、总氮、蛋白质含量提高,烟碱和K+、Ca2+、Mg2+、Cl-含量降低,糖氮比、糖碱比、氮碱比等比例失调,因而降低了烤烟的商品价值和化学品质。当土壤中的砷含量达到100 mg/kg时,烤烟的生长发育受到严重抑制,丧失了生产价值;当砷含量达到200 mg/kg以上时,烤烟不能移栽成活;使烤烟减产10%的土壤砷含量阈值为16.89 mg/kg。砷在烤烟叶片中的积累规律为下部叶>中部叶>上部叶,有39.58%的砷残留在灰分中,其余60.42%存在于烟气中。若以食品中砷含量≤0.5 mg/kg为参照,下、中、上部叶片中砷含量≤0.5 mg/kg时的土壤砷含量阈值分别为2.63,6.56,13.91 mg/kg,中部叶燃烧后烟气中砷含量≤0.5 mg/kg时的土壤砷含量阈值为12.90 mg/kg。

Effects of arsenic on development and yield and quality of flue-cured tobacco

A systematic experiment was conducted by pot experiments to determine the effects of arsenic toxicity on development,yield and quality of flue-cured tobacco.The results showed that arsenic toxicity inhibited development of flue-cured tobacco.It delayed the growing process,and decreased leaves,leaf area,plant height,and yield.Besides,it decreased economic properties,such as output value per plant,average price,and ratio of high level,and chemical quality properties such as increase in total sugar,reduce sugar,total nitrogen,and nicotine.It also decreased content of potassium,calcium,magnesium and chlorine.Therefore,it resulted in disproportion of sugar-nitrogen,nitrogennicotine,sugar-nicotine and potassium-chlorine.And hence,arsenic induced decrease both in economic value and in chemical value.The results also showed that when flue-cured tobacco was planted in soil added to 100 mg/kg of arsenic,it was so affected that there was no production value.When soil was added more than 200 mg/kg of arsenic;flue-cured tobacco could not grow.When soil was added 16.89 mg/kg of arsenic;yield was decreased by 10%.Arsenic content in leaves increased with arsenic addition in soil.Accumulation of arsenic in leaves of flue-cured tobacco was first from lower leaves,to cutters,and then to upper leaves.After cutters were burned at 300 temperatures,residues of arsenic in ash were 39.58%,the remaining(60.42%) were inbreathed by smokers or entered into the air.The arsenic residues in lower leaves,cutters,upper leaves and smoke of cutters was less than 5 mg/kg specified in food hygienic standard,when the critical content of arsenic applied in soil was 2.63,6.56,13.91 and 12.90 mg/kg,respectively.