Table 2. The effects of multiple variables on WUE of wheat and maize.
| Crop | Item† | Estimate | SD | DF | t value | p value | Sign‡ |
|---|---|---|---|---|---|---|---|
| Wheat | α (Intercept) | 1.01 | 0.24 | 513.00 | 4.23 | 0.000 | *** |
| β1 (Plastic) | 0.15 | 0.05 | 49.00 | 3.16 | 0.003 | ** | |
| β1 (Straw) | 0.15 | 0.03 | 49.00 | 4.66 | 0.000 | *** | |
| β2 (SOM) | −0.01 | 0.06 | 513.00 | −0.25 | 0.806 | NS | |
| β3 (Temperature) | −5E-03 | 0.01 | 513.00 | −0.37 | 0.715 | NS | |
| β4 (Water) | −1E-03 | 0.00 | 513.00 | −4.63 | 0.000 | *** | |
| β5 (N) | 2E-03 | 0.00 | 513.00 | 3.62 | 0.000 | *** | |
| β6 (W*N) | 4E-06 | 0.00 | 513.00 | 2.06 | 0.040 | * | |
| Maize | α (Intercept) | −0.85 | 0.82 | 725.00 | −1.03 | 0.302 | NS |
| β1 (Plastic) | 0.61 | 0.06 | 44.00 | 9.86 | 0.000 | *** | |
| β1 (Straw) | 0.19 | 0.05 | 44.00 | 4.07 | 0.000 | *** | |
| β2 (SOM) | 0.31 | 0.16 | 37.00 | 1.97 | 0.056 | NS | |
| β3 (Temperature) | 0.06 | 0.03 | 725.00 | 1.94 | 0.053 | NS | |
| β4 (Water) | −8E-05 | 0.00 | 725.00 | −0.40 | 0.693 | NS | |
| β5 (N) | 4E-03 | 0.00 | 725.00 | 6.36 | 0.000 | *** | |
| β6 (W*N) | −4E-06 | 0.00 | 725.00 | −3.96 | 0.000 | *** |
†See formula (5) for explanation of the items.
‡“***” means p < 0.001, “**” means 0.001 < p < 0.01, “*” means 0.01 < p < 0.05 and “NS” means p > 0.05.