| To scientifically evaluate risks of heavy metal contamination on farmlands in the coal mining areas, we introduced a synergetic assessment model for heavy metal contamination in soil-plant system on the basis of farmland ecological safety, crop production safety and quality safety of agricultural products. The results showed that, according to the ecological risk index of heavy metal pollution, the soil comprehensive ecological risk index was 239.60 for F1 sample plot (mine water contaminated farmland), and 178.42 for F2 sample plot (the coal waste rock contaminated farmland), both of which reached moderate risk levels. The soil comprehensive ecological risk index of F3 sample plot (farmland close to the highway) reached subtle risk level. For wheat grains, the heavy metal comprehensive contamination indexes all reached severe risk levels in F1, F2 and F3 sample plots. According to synergetic assessment model of soil-plant system, the value of pollution degree in F1 sample plot was for 48.4, reaching a high risk level; the value in F2 sample plot was for 54.4, as a moderate risk level; and the value F3 sample plot was for 76.8, at a subtle risk level. |