Table 3.
Extractable metal concentrations in the soils (mg/kg).
| Soil type | Extraction methods | Cu | Zn | Pb | Cd | Fe | Mn |
|---|---|---|---|---|---|---|---|
| Range (median) | Range (median) | Range (median) | Range (median) | Range (median) | Range (median) | ||
| R | DTPA (n = 36) | 1.3–253 (8.2) | 1.3–32.9 (5.3) | 2.2–92.0 (11) | 0.05–5.2 (0.27) | 18.6–166 (43) | 8.5–191 (46) |
| EDTA (n = 36) | 1.9–409 (15.0) | 1.9–149 (8.7) | 5.1–192 (27.4) | 0.06–8.0 (0.4) | 55.3–480 (162) | 53.6–2056 (207) | |
| HCl (n = 33) | 1.7–150 (7.1) | 2.3–41.5 (9.7) | 2.4–79.7 (10.5) | 0.07–2.7 (0.3) | 22.4–534 (118) | 41.0–276 (92) | |
| NH4OAC (n = 36) | Ud-31 (0.42) | Ud-5.9 (0.14) | Ud-4.5 (0.07) | 0.03–1.5 (0.11) | Ud-1.8 (0.03) | 0.08–104 (20.6) | |
| NH4NO3 (n = 36) | Ud-14.9 (0.04) | Ud-15.0 (0.7) |
Ud-8.8 – |
Ud-0.5 (0.02) |
Ud-4.7 – |
0.08–133 (20.9) | |
| W | DTPA (n = 25) | 1.7–145 (5.0) | 1.2–24.7 (3.3) | 3.2–47.8 (7.8) | 0.06–1.1 (0.2) | 16.4–90.8 (43.3) | 7.5–79 (23.2) |
| EDTA (n = 25) | 3.6–321 (8.4) | 1.4–64.9 (3.4) | 5.3–93.0 (15.5) | 0.05–1.6 (0.19) | 68.6–354 (152) | 16.5–690 (100) | |
| HCl (n = 24) | 2.4–231 (6.3) | 2.3–48.2 (4.9) | 3.7–47.5 (9.8) | 0.08–1.6 (0.22) | 67.2–369 (174) | 20.8–181 (72.3) | |
| NH4OAC (n = 25) | 0.1–10.4 (0.26) | Ud-1.7 (0.18) |
Ud-2.4 – |
0.02–0.6 (0.06) |
Ud – |
0.8–41.6 (7.5) | |
| NH4NO3 (n = 25) | Ud-1.5 (0.04) | 0.04–4.4 (1.2) | Ud-2.7 (0.1) | Ud-0.2 (0.04) | Ud-1.8 (0.23) | 0.3–54.8 (11.5) | |
| P | DTPA (n = 20) | 1.8–123 (13.7) | 0.8–31.3 (5.3) | 3.8–105 (12.2) | 0.07–11 (0.33) | 24.6–324 (112) | 5.5–69.6 (15.5) |
| EDTA (n = 20) | 5.0–223 (24.5) | 1.6–74.2 (7.8) | 8.5–177 (25.2) | 0.07–15 (0.43) | 52.2–503 (255) | 17.7–794 (179) | |
| HCl (n = 18) | 3.6–173 (14.0) | 2.7–53.2 (11.3) | 3.1–95.8 (13.6) | 0.1–13.4 (0.4) | 16.1–1060 (335) | 14.5–383 (104) | |
| NH4OAC (n = 20) | Ud-6.3 (0.3) |
Ud-10.2 – |
Ud-3.3 (0.2) | 0.01–3.7 (0.1) |
Ud – |
0.02–15.3 (3.7) | |
| NH4NO3 (n = 20) | Ud-2.2 (0.08) | Ud-30.4 (0.5) | Ud-2.4 (0.02) | Ud-1.4 (0.05) |
Ud-0.2 – |
0.2–35.5 (4.7) |
Ud under detection limit, – more than half of samples did not exceed the detection limit.