| Treatment | Seed yield (kg∙ha−1) | |||
| No | Amendments | 2012 | 2013 | 2014 |
| 1 | Control (no amendment) | 1825 | 4602 | 2580 |
| 2 | N only―100 kg N ha−1 (using 34-0-0) | 1766 | 4831 | 2552 |
| 3 | P only―20 kg P ha−1 (using 0-45-0) | 2217 | 6034 | 3019 |
| 4 | N + P―100 kg N ha−1 + 20 kg P ha−1 | 2748 | 7436 | 4923 |
| 5 | Penicillium bilaiae + 100 kg N ha−1 | 1768 | 4862 | 2583 |
| 6 | Rock P granular (BC Mines) at 20 kg P ha−1 + 100 kg N ha−1 | 1597 | 4644 | 2475 |
| 7 | Rock P granular (BC Mines) at 20 kg P ha−1 + 100 kg N ha−1 + Penicillium bilaiae | 1646 | 4849 | 2623 |
| 8 | Rock P finely-ground (BC Mines) at 20 kg P ha−1 + 100 kg N ha−1 | 1705 | 4732 | 2600 |
| 9 | Rock P finely-ground (BC Mines) at 20 kg P ha−1 + 100 kg N ha−1 + Penicillium bilaiae | 1636 | 4866 | 2552 |
| 10 | Wood ash at 2 Mg∙ha−1 | 2025 | 5403 | 3038 |
| 11 | Wood ash at 2 Mg∙ha−1 + 100 kg N ha−1 | 2378 | 5734 | 3600 |
| 12 | Wood ash at 2 Mg∙ha−1 + 100 kg N ha−1 + 20 kg P ha−1 | 2990 | 7191 | 4782 |
| 13 | Alfalfa pellets at 3.5 Mg∙ha−1 | 2066 | 5494 | 3614 |
| 14 | Compost at 8 Mg∙ha−1 | 2392 | 6178 | 3032 |
| 15 | Thin stillage at 20,000 L∙ha−1 | 3133 | 7380 | 5010 |
| 16 | Distiller grain (wheat)―dry at 2 Mg∙ha−1 | 2883 | 7273 | 5197 |
| 17 | MykePro | 1410 | 4300 | 2511 |
| 18 | MykePro + 100 kg N ha−1 | 1941 | 4991 | 2517 |
| 19 | Bone meal | 1868 | 5091 | 2672 |
| 20 | Bone meal + 100 kg N ha−1 | 2170 | 5631 | 3569 |
|
| LSD0.05 | 297 | 691 | 543 |
|
| SEM | 104.9*** | 244.1*** | 191.7*** |