| Treatment | Class | |
| Prime | Marginal | |
| Monocultures |
|
|
| Switchgrass (SG) | 3.4 | 2.3 |
| Prairie cordgrass (PC) | 4.4 | 8.4 |
| Cup plant (CP) | 2.9 | 7.7 |
| Binary mixtures |
|
|
| SG/CP | 2.9 | 5.3 |
| PCG/CP | 3.3 | 7.7 |
| Tertiary mixture |
|
|
| SG/PCG/CP | 3.4 | 6.3 |
| lsd (0.05) | 0.8 | 2.0 |