关键词: 农业基地, 重金属污染, 地累积指数, 潜在生态危害指数

Abstract: 146 soil samples were collected from the organic agricultural soil base of Renhuai city, Guizhou province, and the pH and concentrations of As,Hg,Cu,Cr,Cd and Pb were measured and analyzed by geoaccumulation index, Hakanson potential ecological index, correlation analysis, PCA analysis and cluster analysis to assess soil pollution levels and potential ecological risks of heavy metals. The result showed that the average contents of As,Hg,Cu,Cr,Cd and Pb in Renhuai city have not exceeded the national farmland environmental quality evaluation standards for edible agricultural products, but the average contents of Cd and Pb were 1.05 and 2.14 times higher than soil background value of Zunyi city. The assessment of geoaccumulation index method demonstrated that the average contents of heavy metals As,Hg,Cu,Cr,Cd and Pb in organic soil base of Renhuai were not higher than national edible agricultural products environmental quality evaluation criteria. However, the evaluation of the accumulation index showed that only the Igeo value of the Pb element in the organic agricultural soil base in Renhuai was 1, and other heavy metal elements have not been polluted, the whole soil environment was in the condition of non-pollution. Hakanson potential ecological risk assessment indicated that the organic agriculture soil base of Renhuai city was in slight potential ecological risk, and Cd and Hg were the dominant factor attributing to the potential ecological risk of organic agriculture soil base. PCA analysis, cluster analysis and correlation analysis showed that high heavy metals pollution towns of Pb,Cr,Cu and As were JC and LJ; high pollution towns of Cd were SH and ST. Heavy metals combined pollution between Pb and Cr; Cu,As and Hg, Cu were detected in this research, which should be concerned by relevant department.

Key words: farming base, heavy metal pollution, geoaccumulation index, potential ecological risk index