Variation of Soil Nutrient and Heavy Metal Accumulation in Greenhouse Soil with Cultivation Years and Analysis on Main Pollution Factors

Jing Yongping; Li Yan; Bo Luji; Zhang Yingpeng; Sun Ming; Zhong Ziwen; Zhang Baisong

doi:10.14083/j.issn.1001-4942.2016.04.016

Abstract：In order to study the effects of different cultivation years on soil nutrient and heavy metal ac-cumulation,and also the main pollution factors in greenhouse,the experiments were conducted to investigate the variation of soil available nitrogen,phosphorus and potassium contents,organic matter content,pH value and heavy metal accumulation quantity in different cultivation -year greenhouses.The correlations between cultivation years and soil physicochemical properties and heavy metal accumulation were also analyzed.The results showed that with the increase of cultivation years,the contents of available nitrogen,phosphorus and potassium and organic matter were significantly increased,and the available nitrogen,phosphorus and potassi-um contents were 2.5 ~3.5,33.9 ~70.3 and 4.5 ~5.6 times of those before the construction of greenhouses respectively.The pH value reduced significantly,and fell about 0.038 units per year.The contents of Cd,Cu and Zn increased significantly,and the Cd content seriously exceeded the grade II level of GB 15618 -1995 (6.5 <pH <7.5),while the Cu and Zn contents were higher than the background values.The soil available nitrogen,available phosphorus and organic matter contents had significantly positive correlations with the Cd, Cu and Zn contents,which suggested that they might have the similar sources.In conclusion,the problems such as unbalance of soil nutrient,acidification and heavy metal accumulation appeared in all the greenhouses with different cultivation years;the available nitrogen,phosphorus and potassium,and Cd were the main pol-lution factors,while Cu and Zn were the potential ones.The rational scientific fertilization methods should be advocated to protect the ecological enviroment of greenhouses.