Table 2.
Eigenvalue and variance contribution rate of different types of soil data
| PCA | Soil types | Eigenvalue | Variance contribution (%) | Accumulative contribution (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| FD | WPT-FD | WPT-FD-HA | FD | WPT-FD | WPT-FD-HA | FD | WPT-FD | WPT-FD-HA | ||
| PCA1 | Mixed soil | 6.91 × 10–6 | 3.62 × 10–5 | 1.46 | 74.82 | 84.01 | 90.00 | 74.82 | 84.01 | 90.00 |
| PCA2 | 9.76 × 10–7 | 1.55 × 10–6 | 0.18 | 10.56 | 6.02 | 5.00 | 85.38 | 90.03 | 95.00 | |
| PCA3 | 4.36 × 10–7 | 4.26 × 10–7 | 1.64 × 10–7 | 4.72 | 4.11 | 2.00 | 90.10 | 94.14 | 97.00 | |
| PCA4 | 2.72 × 10–7 | 1.16 × 10–7 | 1.04 × 10–7 | 2.95 | 1.30 | 0.75 | 93.04 | 95.42 | 97.75 | |
| PCA5 | 1.26 × 10–7 | 4.55 × 10–8 | 6.93 × 10–7 | 1.36 | 0.12 | 0.23 | 94.41 | 95.56 | 98.99 | |
| PCA1 | Loessial soil | 3.39 × 10–6 | 1.56 | 2.82 × 10–5 | 77.00 | 88.81 | 95.88 | 77.00 | 88.71 | 95.88 |
| PCA2 | 6.21 × 10–7 | 0.20 | 8.54 × 10–7 | 10.41 | 6.19 | 2.90 | 87.41 | 94.90 | 98.79 | |
| PCA3 | 4.85 × 10–7 | 0.07 | 1.28 × 10–7 | 6.15 | 2.09 | 0.43 | 93.56 | 96.99 | 99.22 | |
| PCA4 | 1.92 × 10–7 | 6.56 × 10–4 | 5.79 × 10–8 | 3.23 | 0.73 | 0.20 | 96.79 | 97.99 | 99.42 | |
| PCA5 | 1.70 × 10–8 | 3.64 × 10–4 | 4.56 × 10–8 | 0.86 | 0.51 | 0.16 | 97.65 | 98.50 | 99.57 | |
| PCA1 | Sandy soil | 9.11 × 10–6 | 4.71 × 10–5 | 1.34 | 86.94 | 89.27 | 90.75 | 86.94 | 89.27 | 90.75 |
| PCA2 | 6.36 × 10–7 | 2.77 × 10–6 | 0.15 | 6.07 | 5.26 | 8.75 | 93.01 | 94.53 | 99.50 | |
| PCA3 | 2.12 × 10–7 | 1.86 × 10–6 | 6.65 × 10–7 | 2.02 | 3.51 | 0.26 | 95.03 | 98.04 | 99.76 | |
| PCA4 | 1.45 × 10–7 | 7.57 × 10–7 | 2.41 × 10–7 | 1.39 | 1.43 | 0.10 | 96.41 | 99.48 | 99.86 | |
| PCA5 | 1.01 × 10–8 | 8.32 × 10–8 | 1.61 × 10–7 | 1.05 | 0.16 | 0.05 | 97.46 | 99.64 | 99.90 | |