Effects of Livestock Farms on Heavy Metal Pollution in Farmland Soils

The farmland soils around three typical livestock farms in Jilin province were studied to elucidate the impact of farms on heavy metal pollution in surrounding farmland soils. The results showed that the average content of Cd was maximal in the soils around cattle farm (0.29 mg kg-1); the average value of Pb was highest in the soils around the pig farm; and Cu, Zn, Ni and Cr were all highest in the soils around the chicken farm. The distribution of heavy metals in the soils around different livestock farms varied greatly. The contents of Cu, Zn, Ni and Cr decreased in the same order: chicken farm> pig farm > cattle farm, but Pb was pig farm> chicken farm> cattle farm, and Cd was cattle farm> pig farm> chicken farm. These results indicated that the livestock farms did not cause significant heavy metal pollution in its surrounding agricultural soils, but the accumulation of heavy metals caused by farms should arouse the attention.