Assessment of Heavy Metal Pollution in Vegetable Greenhouse in Lishi District

With different planting years in Lishi District vegetable greenhouse soil as the research object,method of application of single pollution index and comprehensive quality index combines the pollution evaluation of 7heavy metals in surface soil in greenhouse.The results showed that the content of heavy metals in the soil increased with the increase in planting;limit the average content of heavy metals were lower than the standard greenhouse vegetable producing environmental quality standards;greenhouse soil Cd,Pb,Ni exceed the standard phenomenon.Combined with the single quality index of the heavy metals and comprehensive quality index(0.64),the soil environment quality in vegetable greenhouse Lishi District greenhouse was classified at level two,which was still clean level.