| Explanatory variable | Function |
| Upland rice area (ha) | 1.479 |
| Upland rice plots (plots) | −1.017 |
| Productivity (kg per ha) | 0.815 |
| Annual production (kg) | −0.984 |
| Rice shortage (months) | −0.165 |
| Farming technique (5 levels) | 0.149 |
| Farming water (5 levels) | −0.406 |