Table 7.
Contents of nutrients and heavy metals in soils in the vicinity of sample pig farms.
| Crop | Treatment | TN (g kg−1) | TP (g kg−1) | AN (mg kg−1) | AP (mg kg−1) | Cu (mg kg−1) | Zn (mg kg−1) | Cd (mg kg−1) | Pb (mg kg−1) | |
|---|---|---|---|---|---|---|---|---|---|---|
| Vegetable | CK | Range | 0.78–1.25 | 0.61–0.68 | 115.3–157.7 | 33.2–85.9 | 16.5–36.5 | 82.1–90.3 | 0.07–0.12 | 21.7–22.8 |
| Mean | 1.03 | 0.66 | 136.7 | 58.5 | 28.5 | 88.3 | 0.10 | 22.3 | ||
| T | Range | 1.79–2.85 | 1.05–3.91 | 209.7–318.9 | 121.2–349.6 | 80.2–168.7 | 166.0–344.5 | 0.12–0.27 | 22.3–43.0 | |
| Mean | 1.92 | 1.27 | 241.9 | 244.7 | 112.9 | 253.4 | 0.17 | 31.6 | ||
| Grade II of soil heavy metal ① | 0 | 16.7% | 100% | 100% | ||||||
| Standards of soil heavy metal in America | 0 | 0 | 100% | 100% | ||||||
| Standards of soil heavy metal in Holland | 0 | 0 | 100% | 100% | ||||||
| Paddy | CK | Range | 0.78–1.74 | 0.42–0.61 | 117.7–165.3 | 18.4–56.2 | 12.2–26.5 | 27.5–72.4 | 0.01–0.18 | 2.9–8.5 |
| Mean | 1.46 | 0.52 | 136.5 | 39.5 | 20.2 | 48.3 | 0.07 | 4.2 | ||
| T | Range | 1.25–3.15 | 0.33–2.91 | 115.0–307.2 | 120.4–373.2 | 13.6–80.2 | 67.7–249.8 | 0.11–0.99 | 28.5–53.5 | |
| Mean | 2.14 | 1.15 | 261.3 | 253.6 | 33.5 | 102.3 | 0.22 | 35.9 | ||
| Grade II of soil heavy metal ① | 86.3% | 87.1% | 91.7% | 100% | ||||||
| Standards of soil heavy metal in America | 96.6% | 71.3% | 100% | 100% | ||||||
| Standards of soil heavy metal in Holland | 67.8% | 64.4% | 97.7% | 100% |
① According to the soil environmental quality standards of China (GB15618-1995).