| Season |
| Nitrogen rate | |||
| N0 | N1 | N2 | N3 | ||
| kg∙ha−1 | |||||
| 2003/4 | Pre-planting | 0 | 42 | 85 | 75 |
|
| Planting (10/24/03) | 31 | 28 | 50 | 60 |
|
| Hilling (12/15/03) | 0 | 36 | 44 | 68 |
|
| Total | 31 | 106 | 179 | 203 |
| 2004/5 | Pre-planting | 0 | 0 | 0 | 0 |
|
| Planting (10/04/04) | 0 | 31 | 63 | 126 |
|
| Hilling (11/26/04) | 0 | 31 | 63 | 126 |
|
| Total | 0 | 62 | 126 | 252 |
| 2005/6 | Pre-planting (9/30/05) | 0 | 0 | 0 | 47 |
|
| Planting (10/20/05) | 23 | 42 | 79 | 93 |
|
| Hilling (11/29/05) | 0 | 42 | 79 | 150 |
|
| Total | 23 | 84 | 158 | 290 |
| 2006/7 | Pre-planting (10/18/06) | 0 | 0 | 0 | 47 |
|
| Planting (11/05/06) | 0 | 31 | 47 | 93 |
|
| Hilling (12/10/07) | 0 | 31 | 80 | 113 |
|
| Total | 0 | 62 | 127 | 253 |