Table 5 Linear correlation coefficient (r) between root volume, surface area, root area, root length, root diameter and different methods
Root volume1 (mm3) | Trench | Volumetric ring | Hand Auger hole | Monolith |
|---|---|---|---|---|
Trench | 0.914* | 0.514 | − 0.110 | |
Volumetric ring | 0.914* | 0.763 | − 0.252 | |
Hand Auger hole | 0.514 | 0.763 | − 0.467 | |
Monolith | − 0.110 | − 0.252 | − 0.467 | |
Root area1 (mm−2) | ||||
Trench | − 0.254 | 0.228 | 0.042 | |
Volumetric ring | − 0.254 | 0.526 | 0.026 | |
Hand Auger hole | 0.228 | 0.526 | − 0.107 | |
Monolith | 0.042 | 0.026 | − 0.107 | |
Root length1 (m) | ||||
Trench | − 0.216 | 0.540 | 0.318 | |
Volumetric ring | − 0.216 | 0.277 | 0.124 | |
Hand Auger hole | 0.540 | 0.277 | 0.356 | |
Monolith | 0.318 | 0.124 | 0.356 | |
Root diameter1 (mm) | ||||
Trench | 0.074 | 0.449 | − 0.027 | |
Volumetric ring | 0.074 | − 0.692 | − 0.502 | |
Hand Auger hole | 0.449 | − 0.692 | 0.308 | |
Monolith | − 0.027 | − 0.502 | 0.308 |