Table 3.
Treatment effects on the dry matter (DM) and heavy metal content of maize shoots.
| Moisture levels | Biochar rates (%) | DM mg pot−1 | Heavy metals |
||||
|---|---|---|---|---|---|---|---|
| Fe | Mn | Zn | Cu | Cd | |||
| Shoot heavy metal concentrations (mg kg−1) | |||||||
| 75% FC | 0.0 | 490 | 151 | 62.5 | 268 | 8.60 | 4.13 |
| 1.0 | 757 | 181 | 43.4 | 248 | 6.27 | 3.33 | |
| 3.0 | 857 | 168 | 34.9 | 207 | 5.00 | 2.40 | |
| 5.0 | 990 | 153 | 30.5 | 193 | 3.47 | 1.93 | |
| LSD1 | 307 | NS | 10.6 | 60.2 | 3.47 | NS | |
| 100% FC | 0.0 | 624 | 264 | 88.7 | 328 | 11.5 | 5.93 |
| 1.0 | 890 | 172 | 55.7 | 326 | 7.40 | 5.73 | |
| 3.0 | 957 | 219 | 44.4 | 277 | 7.60 | 4.27 | |
| 5.0 | 757 | 196 | 35.1 | 259 | 8.13 | 3.13 | |
| LSD1 | 260 | 81.2 | 21.6 | 68.7 | 3.08 | 2.55 | |
| LSD2 | NS | 41.7 | NS | 36.3 | 2.06 | 1.28 | |
| Metal uptake by shoots (μg plant−1) | |||||||
| 75% FC | 0.0 | 35.8 | 15.4 | 65.1 | 2.08 | 1.01 | |
| 1.0 | 63.1 | 16.7 | 99.9 | 2.21 | 1.46 | ||
| 3.0 | 71.9 | 14.7 | 87.3 | 2.17 | 0.99 | ||
| 5.0 | 75.9 | 15.0 | 95.4 | 1.71 | 0.95 | ||
| LSD1 | 27.7 | NS | NS | NS | NS | ||
| 100% FC | 0.0 | 80.2 | 27.4 | 102 | 3.50 | 1.79 | |
| 1.0 | 74.5 | 24.5 | 144 | 3.15 | 2.55 | ||
| 3.0 | 105 | 21.2 | 133 | 3.64 | 2.04 | ||
| 5.0 | 73.2 | 13.4 | 98.0 | 3.03 | 1.18 | ||
| LSD1 | 28.9 | 10.3 | NS | NS | 1.19 | ||
| LSD2 | 16.6 | 4.90 | 25.0 | 0.39 | 0.56 | ||
LSD1: least significance difference at p = 0.05 for biochar effect; LSD2: least significance difference at p = 0.05 for moisture effect; NS: not significant; ND: not detectable.