温室土壤pH值及重金属含量变化研究

温室土壤pH值及重金属含量与温室种植年限关系研究结果表明,温室土壤pH值下降趋势明显,土壤pH平均值从露地土壤的6.53降低至建成温室后的5.48。温室土壤的重金属Pb、Cd含量明显高于露地土壤,其平均值分别为露地土壤的1.39倍和1.93倍。随温室种植年限的增加,温室土壤pH值呈下降趋势,而Pb、Cd的含量不断提高。当温室种植蔬菜超过16年时,土壤中Cd含量超过土壤重金属元素Cd含量的临界值。

Research on Changing Law of pH Value and Contents of Heavy Metals in Greenhouse Soil

The relationship among accumulation of heavy metals,soil pH value and greenhouse planting time were studied in this paper,the results showed that,soil pH value decreased significantly,which changed from 6.53 to 5.48 after greenhouse had been set up.Contents of heavy metals Pb,Cd in greenhouse soil were significantly higher than the open field soil,which were 1.39,1.93 times of the open field soil respectively.The pH value of the greenhouse soil decreased continuously as planted age increased,and the contents of heavy metals Pb,Cd increased continuously as planted age increased.The content of heavy metal Cd had exceeded the critical point when the greenhouse was cultivated over 16 years.