| Location | Change in soil K level† | Soil test category* | |
| ppm | Spring | Fall | |
| Buffalo | 84.5 ± 5.35‡ | Medium | Very low |
| Gardner | 83.5 ± 4.44 | Medium | Very low |
| Walcott E | 71.1 ± 2.87 | Medium | Very low |
| Wyndmere | 67.2 ± 3.85 | Medium | Very low |
| Fairmount | 107 ± 3.85 | High | Very low |
| Milnor | 66.3 ± 2.53 | Medium | Low |
| Walcott W | 25.8 ± 10.6 | Low | Low |
| Arthur | 134 ± 9.66 | Very high | very low |
| Page | 139 ± 7.79 | Very high | Very low |
| Valley City | 265 ± 67.0 | Very high | Very high |