Table 6.
Variable importance for projection of soil factors affecting the potato tuber yield.
| Indicators | Correlation coefficient | Variable importance in projection | Variable importance in projection order |
|---|---|---|---|
| SNNC | 0.06 | 0.153 | 12 |
| SANC | −0.15 | 0.398 | 10 |
| SAHC | −0.02 | 0.057 | 13 |
| SOM | 0.26 | 0.701 | 9 |
| AK | 0.11 | 0.298 | 11 |
| AP | −0.33 | 0.905 | 7 |
| pH | −0.56** | 1.513 | 2 |
| SEC | −0.44* | 1.187 | 4 |
| SWC | 0.28 | 0.752 | 8 |
| SUA | 0.37 | 1.010 | 6 |
| SPA | 0.40* | 1.100 | 5 |
| SSA | 0.55** | 1.510 | 3 |
| SCA | 0.60** | 1.625 | 1 |
*means significant correlation at 0.05 level, **means significant correlation at 0.01 level. SNNC, soil nitrate-N content; SANC, soil ammonium-N content; SAHC, soil alkali-hydrolyzable nitrogen content; SOM, soil organic matter; AK, soil available potassium; AP, soil available phosphorus; pH, soil pH value; SEC, soil electrical conductivity; SWC, soil water content; SUA, soil urease activity; SPA, soil phosphatase activity; SSA, soil sucrase activity; SCA, soil catalase activity.