Table 2.
Model features of pH, organic matter content (OM) percentage and C/N ratio.
| Response parameter | Regression | Standard deviation S | R2(%) | Adjusted R2 (%) |
Predicted R2 (%) |
Predicted squares sum |
|---|---|---|---|---|---|---|
| pH | Linear | 0.4852 | 59.18 | 10.19 | 0 | 10.2330 |
| Quadratic | 0.3659 | 81.42 | 48.91 | – | – | |
| Full Cubic | 0.0011 | 100 | 100 | 99.99 | 0.0004 | |
| Special Quartic | 0.3659 | 81.42 | 48.91 | – | – | |
| OM | Linear | 14.7044 | 44.12 | 0 | 0 | 8564.280 |
| Quadratic | 8.1604 | 89.67 | 62.14 | – | – | |
| Full Cubic | 0.1542 | 100 | 99.99 | - | 29.060 | |
| Special Quartic | 0.3593 | 99.93 | 99.93 | – | 153.691 | |
| C/N | Linear | 3.4564 | 21.13 | 0 | 0 | 327.132 |
| Quadratic | 1.5782 | 86.85 | 63.83 | 0 | 124.045 | |
| Full Cubic | 0.3344 | 99.56 | 98.38 | 94.09 | 4.477 | |
| Special Quartic | 1.5782 | 86.85 | 63.83 | 0 | 124.045 |