Numberz of sycamore roots (> 5 mm [0.3 in] diameter) occurring at different depths adjacent to sidewalks with various root barriers in two soil types. Percentage of sycamore roots (> 5 mm [0.3 in] diameter) occurring at different depths is indicated in parentheses.
| Depth from soil surface | No barrier | Biobarrier™ | Deep Root™ | Gravel | Polyethylene |
|---|---|---|---|---|---|
| Well-drained soil | |||||
| ≤10 cm | 34 by (50) | 34 b (48.6) | 17 b (35.4) | 0 a (0) | 22 b (39.3) |
| ≥ 10–30 cm | 34 a (50) | 36 a (51.4) | 31 a (64.6) | 23 a (100) | 34 a (60.7) |
| Total number | 68 b | 70 b | 48 b | 23 a | 56 b |
| Poorly drained soil | |||||
| ≤10 cm | 42 b (29) | 11 a (15.3) | 38 b (45.8) | 15 a (16.8) | 20 ab (20.8) |
| ≥ 10–30 cm | 103 a (71) | 61 a (84.7) | 45 a (54.2) | 74 a (83.2) | 76 a (79.2) |
| Total number | 145 b | 72 a | 83 a | 89 a | 96 a |
| Statistical significance | |||||
| Treatments | P < 0.05 | ||||
| Soil type | P < 0.05 | ||||
| Treatments × soil type | P < 0.04 | ||||