| N source | Amendment rate | Total N rate | N-treatment |
|
| kg∙ha−1 | kg N ha−1 |
|
| None | 0 | 0 | none |
| Urea | 98 | 45 | Urea-45 |
| Urea | 195 | 90 | Urea-90 |
| Urea | 292 | 135 | Urea-135 |
| Urea | 382 | 180 | Urea-180 |
| PPB | 2240 | 45 | PPB-45 |
| PPB | 4480 | 90 | PPB-90 |
| PPB | 6720 | 135 | PPB-135 |
| PPB | 8480 | 180 | PPB-180 |