Table 5.
Element concentration in wood ash used in this study and that from reported values given as mean, a 95% confidence interval (CI), and median.
| This study | Reported values | ||||
|---|---|---|---|---|---|
| Mean | 95% CI | Median | n | ||
| Total N (g kg−1) | 5.3 (0.3) | 3.1 | 1.4 | 3.0 | 14 |
| P (g kg−1) | 5.0 (0.2) | 11.27 | 0.9 | 10.0 | 214 |
| K (g kg−1) | 46.7 (1.7) | 43.9 | 3.5 | 39.0 | 236 |
| Ca (g kg−1) | 52.5 (1.0) | 165.8 | 11.4 | 160.0 | 227 |
| Mg (g kg−1) | 11.7 (1.2) | 17.5 | 1.5 | 17.0 | 222 |
| Na (g kg−1) | 1.4 (0.1) | 10.0 | 1.6 | 8.3 | 173 |
| Al (g kg−1) | 7.4 (1.4) | 25.6 | 3.2 | 19.0 | 168 |
| Fe (g kg−1) | 3.3 (0.8) | 22.1 | 5.6 | 12.0 | 206 |
| Mn (g kg−1) | 2.3 (0.3) | 8.9 | 0.9 | 7.7 | 225 |
| Cr (mg kg−1) | 12.5 (1.3) | 78.9 | 7.1 | 66.3 | 243 |
| Ni (mg kg−1) | 30.6 (2.1) | 43.32 | 5.0 | 35.0 | 243 |
| Cu (mg kg−1) | 122.6 (9.7) | 112.8 | 7.9 | 97.0 | 313 |
| Zn (mg kg−1) | 197 (50) | 2157.1 | 307.9 | 1120.0 | 313 |
| As (mg kg−1) | 17.1 (0.2) | 18.5 | 3.9 | 8.9 | 239 |
Cd and Pb were not detected in wood ash used in this study.
Standard errors are shown in parentheses (n = 3).
Mean, a 95% confidence interval, and median of reported values were calculated using the data of wood and/or bark fuel type ash in Wood Ash Database (http://woodash.slu.se).