|
| Period | 1949-1978 kg N ha−1 | 1979-1989 kg N ha−1 | 1990-1999 kg N ha−1 | 2000-2010 kg N ha−1 |
| Input (A) | Nfe | 67.8 (23.4) | 333.9 (59.1) | 492.5 (79) | 374.3 (86.1) |
| Nma | 169.2 (58.4) | 178.0 (31.5) | 73.2 (11.8) | 0 (0) | |
| Ndep | 7.6 (2.6) | 7.6 (1.3) | 22.8 (3.7) | 38 (8.7) | |
| Nfix | 45 (15.5) | 45 (8) | 33.5 (5.4) | 22.4 (5.2) | |
| Subtotal | 290 (100) | 564 (100) | 622 (100) | 435 (100) | |
| Output (B) | Nharv | 88.7 (71.6) | 142.3 (45) | 157 (38) | 120 (38.1) |
| Ngas | 30.5 (24.6) | 150.2 (47.6) | 221.6 (53.6) | 168.4 (53.5) | |
| Nloss | 4.7 (3.8) | 23.4 (7.4) | 34.5 (8.3) | 26.2 (8.3) | |
| Subtotal | 123.9 (100) | 315.9 (100) | 413 (100) | 314.6 (100) | |
| Balance (A-B) Nsurp | 165.7 | 245.8 | 208.9 | 120.1 | |