| Measurement height | Under ground -6cm | Under ground -4cm | Under ground -2cm | Soil surface 0 | Ground 2cm | Ground 4cm | Ground 6cm | Ground 8cm | Ground 10cm | Ground 12m | Ground 14m | Ground 16cm | Ground 18cm | Ground 20cm | Ground 22m | Ground 24cm | Ground 26m | Ground 28cm | Ground 33cm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total average root collar diameter (cm) | 13.5 | 11.9 | 10.7 | 9.9 | 9.3 | 8.8 | 8.6 | 8.3 | 8.1 | 7.9 | 7.7 | 7.6 | 7.4 | 7.3 | 7.2 | 7.1 | 7.0 | 7.0 | 6.9 |
| Total average standard deviation | 2.0 | 1.7 | 1.5 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.2 | 1.1 | 1.1 | 1.1 | 1.1 | 1.1 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |