井冈蜜柚主产区土壤重金属污染特征及风险评价OA北大核心CSTPCD

To investigate the pollution characteristics and risk of heavy metals in soil of Jinggang honey pomelo orchards,18 representative soil samples were collected from Jinggang pomelo orchards in 4 main production areas of Ji'an City,Jiangxi Province.Soil physicochemical properties and heavy metals(Cd,Ph,As,Hg and Cr)content were determined.The pollution levels of soil heavy metals were evaluated by single factor pollution index,geoaccumulation index and Nemero comprehensive pollution index.The potential ecological risks of soil heavy metals were discussed in potential ecological risk index(RI).The results showed that soil acidification was serious,the fertility was in the middle and lower levels,and the available nitrogen was lack in the study area.The average contents of Cd,Pb,As,Hg and Cr were 0.23,63.81,13.95,0.10 and 167.28 mg·kg-1 in 0 to 20 cm soil,which were 2.30,1.99,1.35,1.25 and 3.49 times of the background values,respectively.The average contents of Cd,Pb,As,Hg and Cr were 0.26,62.40,13.51,0.10 and 167.87 mg·kg-1 in 20 to 40 cm soil,which were 2.60,1.94,1.31,1.25 and 3.50 times of the background values,respectively.There was no significant difference in heavy metal content at different depths.Single factor and geoaccumulation index analysis showed that the accumulation of Cr,Pb and Cd in the soil of the study area was serious,and 11.11％of Cd was seriously polluted.With the standard value as the reference,the soil heavy metal pollution in the study area was mainly mild pollution,belonging to low ecological hazard degree.With the background value as the reference,the soil heavy metal pollution in the study area was mainly moderate and serious,belonging to medorate and strong hazard degrees.The correlation analysis showed that Cr had good homology with Pb and As.Redundancy analysis showed that soil pH and organic matter were the main environmental factors affecting the change of heavy metals in soil of pomelo orchards in Jinggang.Overall,the heavy metal pollution of soil in the study area was light,but there were some orchards exceeding the standard and the accumulation of Cd,Cr and Pb in soil.Fruit farmers and relevant departments should pay more attention and take effective measures to prevent their ecological risks.