Table 2.
Life cycle inventory data per metric ton of corn, soy, and wheat produced in the United States in 1960 and 2010
| 2010 | 1960 | ||||||
|---|---|---|---|---|---|---|---|
| Item | Corn | Soy | Wheat | Corn | Soy | Wheat | |
| Input | |||||||
| Fertilizer (kg) | |||||||
| N | 16.1 | 1.12 | 20.1 | 16.6 | 0.74 | 9.17 | |
| P2O5 | 5.55 | 5.53 | 6.91 | 10.8 | 2.72 | 7.03 | |
| K2O | 5.71 | 7.75 | 1.36 | 8.50 | 3.35 | 3.93 | |
| Sulfur | 0.27 | 0.13 | 0.53 | 0.27 | 0.13 | 0.53 | |
| Lime | 33.5 | 0.00 | 0.00 | 33.4 | 0.00 | 0.00 | |
| Energy | |||||||
| Diesel (L) | 4.49 | 10.9 | 13.2 | 4.47 | 17.5 | 21.3 | |
| Gas (L) | 1.17 | 3.49 | 3.02 | 12.1 | 5.62 | 4.86 | |
| Liquid propane gas (L) | 7.02 | 0.00 | 3.82 | 2.68 | 0.00 | 6.16 | |
| Electricity (kWh) | 4.33 | 0.00 | 11.9 | 0.00 | 0.00 | 19.19 | |
| Total pesticides (kg) | 0.25 | 0.46 | 0.29 | 0.20 | 0.21 | 0.12 | |
| Herbicides | 0.24 | 0.45 | 0.12 | 0.13 | 0.09 | 0.11 | |
| Insecticides | 0.01 | 0.01 | 0.00 | 0.08 | 0.11 | 0.01 | |
| Other (fungicides) | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | |
| Seed (kg) | 2.10 | 23.4 | 34.5 | 20.5 | 45.0 | 41.8 | |
| Output | |||||||
| Nitrous oxide (kg) | 0.46 | 0.25 | 0.55 | 0.49 | 0.27 | 0.36 | |
| Ammonia (kg) | 2.38 | 2.19 | 4.13 | 3.57 | 3.91 | 4.46 | |
| Nitric oxide (kg) | 0.35 | 0.02 | 0.43 | 0.36 | 0.02 | 0.20 | |
| Carbon dioxide (kg) | 17.2 | 0.17 | 3.04 | 14.3 | 0.03 | 0.42 | |
| Nitrate (kg) | 1.44 | 0.00 | 0.00 | 4.49 | 0.00 | 0.00 | |
| Phosphate (kg) | 0.00 | 0.00 | 0.03 | 0.14 | 0.00 | 0.00 | |
| Yield (t) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |