Soil pH Organic matter (%) Total N  (mg·kg-1) Total amount of heavy metals (mg·kg-1) Cd Cu Mn Pb Zn Low- contaminated 4.34 ± 0.07 2.11 ± 0.03 1439.5 ± 123.58  3.07 ± 1.28 323 ± 5.38 139.62 ± 5.23 392 ± 12.13 320 ± 8.52 High- contaminated 3.61 ± 0.02 1.20 ± 0.03  671.19 ± 12.45 10.37 ± 0.26 615 ± 20.27 158.08 ± 4.79 1644 ± 61.12 470 ± 14.25

Low-contaminated and high-contaminated soil samples were collected at 200 and 20 m distant from the discharge channel of mining wastewater, respectively; data are presented as the mean ± SD (n=3).

Table 1: The physicochemical properties of mining-contaminated farmland soil samples.