Table II. Total root length in the 20-cm upper soil layer of the 5-cm middle area between two plants as affected by soil P status, planting distance, and cropping combination on 60 d after sowing (harvest II).
HX3/NE1 and HX3/GZ1 presented for soybean HX3 intercropped with maize NE1 and GZ1, respectively; HX3/HX3, NE1/NE1, and GZ1/GZ1 for HX3, NE1, and GZ1 sole culture, respectively. F value of three-factor ANOVA: 11.24 for P treatment (P < 0.01), 63.61 for cropping combination (P < 0.001), and 736.41 for planting distance (P < 0.001). All the data were the mean of four replicates with se. The same letter after numbers meant not significant within the planting distance at the same P level (P < 0.05).
| Root Length |
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| Cropping System | LP |
SP |
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| 5 × 5 | 10 × 10 | 20 × 20 | 40 × 40 | 5 × 5 | 10 × 10 | 20 × 20 | 40 × 40 | ||
| mm plants−2 | |||||||||
| Intercropping | HX3/NE1 | 244.9 ± 18.7a | 160.3 ± 8.5a | 120.6 ± 11.2a | 24.6 ± 1.3a | 343.8 ± 25.4a | 175.3 ± 13.2a | 125.7 ± 9.1a | 30.1 ± 4.3a |
| HX3/GZ1 | 175.2 ± 12.9c | 85.8 ± 7.1c | 40.3 ± 3.1d | 6.3 ± 0.7c | 156.8 ± 13.3e | 87.3 ± 6.7c | 54.0 ± 2.6c | 2.5 ± 0.7c | |
| Monoculture | HX3/HX3 | 164.5 ± 8.6c | 125.7 ± 9.7b | 82.2 ± 6.3c | 14.1 ± 1.2b | 184.7 ± 13.1d | 135.8 ± 10.8b | 91.6 ± 6.7b | 6.4 ± 0.8c |
| NE1/NE1 | 257.6 ± 11.6a | 133.9 ± 6.6b | 99.6 ± 7.6b | 23.0 ± 2.7a | 232.5 ± 23.2c | 129.5 ± 11.2b | 119.3 ± 8.3a | 16.1 ± 1.6b | |
| GZ1/GZ1 | 211.2 ± 15.9b | 126.2 ± 7.5b | 94.4 ± 6.2bc | 11.7 ± 0.5b | 297.4 ± 17.6b | 126.2 ± 8.6b | 93.3 ± 5.5b | 11.5 ± 1.0b | |