| 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | |
| Grain Yield (Mg ha−1) | |||||||
| CP | 8.7 (0.6) | 8.4 (0.9) | 14.8 (1.1) | 11.1 (1.0) | 8.9 (0.7) | 6.9 (0.6) | 7.0 (0.3) |
| NT | 9.0 (0.3) | 8.0 (0.3) | 13.5 (1.9) | 8.2 (1.3) | 8.8 (0.4) | 4.9 (0.7) | 5.6 (0.4) |
| CPnf | 4.8 (0.4) | 5.0 (0.3) | 6.5 (0.6) | 6.3 (0.9) | 4.9 (0.9) | 3.2 (0.5) | 4.3 (0.3) |
| NTnf | 4.1 (0.1) | 4.0 (0.4) | 5.3 (0.4) | 3.4 (0.2) | 4.3 (0.3) | 2.3 (0.2) | 3.1 (0.2) |
| N Removal (kg ha−1) | |||||||
| CP | 118 (7) | 113 (8) | 153 (8) | 121 (14) | 107 (9) | 74 (7) | 82 (4) |
| NT | 121 (7) | 104 (6) | 139 (25) | 93 (13) | 106 (5) | 51 (7) | 66 (5) |
| CPnf | 48 (5) | 57 (4) | 64 (4) | 63 (12) | 48 (9) | 29 (2) | 38 (4) |
| NTnf | 41 (1) | 45 (5) | 55 (3) | 37 (2) | 44 (3) | 21 (1) | 29 (2) |
| N Fertilizer Removal Efficiency (%) | |||||||
| CP | 37 | 29 | 47 | 31 | 31 | 24 | 23 |
| NT | 42 | 31 | 44 | 29 | 33 | 16 | 19 |