| Control ± S.E. | Low ± S.E. | Intermediate ± S.E. | High ± S.E. |
Ditch number |
| 2, 5, 8 | 1, 4, 7 | 3, 6, 9 |
Daily (˚C) | 11.968 ± 0.254 | 13.425 ± 0.140 | 15.448 ± 0.140 | 16.422 ± 0.150 |
Monthly (˚C) | 12.113 ± 1.038 | 13.480 ± 0.599 | 15.506 ± 0.599 | 16.513 ± 0.599 |