| Type of fixation | N2 fixed (106 metric tons per year) |
| Non-biological | |
| Industrial | about 50 |
| Combustion | about 20 |
| Lightning | about 10 |
| Subtotal of non-biological | about 80 |
| Biological | |
| Agricultural land | about 90 |
| Forest and non-agricultural land | about 50 |
| Sea | about 35 |
| Subtotal of biological | about 175 |
| Total | about 255 |