Table 3.
Comparison of N budget variables between the five categories (see column 1): grain and forage, and legume and non-legume crop combinations for those plots for which the N budget variables were high (see Table 2), “na,” denotes “non-applicable” comparisons.
| N fertilizer (kg N ha−1) | N fixed (kg N ha−1) | N input (kg N ha−1) | N output (kg N ha−1) | N surplus (kg N ha−1) (N-out > 0) | Biomass output (kg N ha−1) | NUE (N-out > 0) | BOE | |
|---|---|---|---|---|---|---|---|---|
| Grain legume | 0.36 ± 0.00 (1.43) | 4.20 ± 0.06 (66.7) | 4.68 ± 0.09 (107.8) | 4.32 ± 0.11 (75.2) | 6.98 ± 17.74 | 7.79 ± 0.20 (2416.3) | 0.12 ± 0.36 (1.13) | 3.57 ± 0.43 (35.5) |
| Grain non-legume | 4.30 ± 0.03 (73.7) | na | 4.44 ± 0.08 (84.8) | 4.06 ± 0.10 (58.0) | −10.08 ± 16.93 | 8.36 ± 0.19 (4272.7) | 0.75 ± 0.35 (2.12) | 5.03 ± 0.42 (152.9) |
| Test | na | na | 24.71 <0.0001 | 14.06 < 0.0001 | 7.96 < 0.0048 | 56.26 < 0.0001 | 38.23 < 0.0001 | 168.3664 < 0.0001 |
| Grain mix | 4.01 ± 0.04 (55.1) | 4.19 ± 0.08 (66.0) | 4.73 ± 0.13 (113.3) | 4.70 ± 0.13 (109.9) | −24.76 ± 19.84 | 8.10 ± 0.22 (3294.5) | 0.15 ± 0.37 (1.16) | 3.45 ± 0.43 (31.5) |
| Grain non-legume | 4.30 ± 0.03 (73.7) | na | 4.33 ± 0.13 (75.9) | 4.06 ± 0.09 (58.0) | −12.74 ± 18.27 | 8.37 ± 0.19 (4315.6) | 0.74 ± 0.34 (2.10) | 5.04 ± 0.41 (154.5) |
| Test | na | na | 61.0749 < 0.0001 | 41.15 < 0.0001 | 1.78 < 0.1820 | 4.45 < 0.0349 | 16.15 < 0.0001 | 78.07 < 0.0001 |
| Forage mix | 4.39 ± 0.18 (80.6) | 4.75 ± 0.26 (115.6) | 5.16 ± 0.14 (174.2) | 4.75 ± 0.26 (115.6) | −20.48 ± 20.80 | 8.61 ± 0.21 (5486.2) | 0.66 ± 0.36 (1.93) | 4.29 ± 0.28 (73.0) |
| Forage non-legume | 4.95 ± 0.17 (141.2) | 2.27 ± 0.33 (9.7) | 4.93 ± 0.15 (138.4) | 4.34 ± 0.26 (76.7) | 28.04 ± 21.16 | 8.44 ± 0.21 (4628.6) | 0.20 ± 0.36 (1.22) | 4.16 ± 0.28 (64.1) |
| Test | 19.77 < 0.0001 | 108.92 < 0.0001 | 8.30 < 0.0040 | 14.29 < 0.0001 | 33.81 < 0.0001 | 8.31 < 0.0039 | 24.867 < 0.0001 | 1.76 < 0.1851 |
| Grain legume + forage | 0.36 ± 0.00 (1.40) | 4.23 ± 0.10 (68.7) | 4.47 ± 0.04 (87.4) | 4.66 ± 0.15 (105.6) | −34.28 ± 4.27 | 8.00 ± 0.12 (2981.0) | 0.34 ± 0.09 (1.40) | 3.65 ± 0.09 (38.5) |
| Grain + forage | na | 3.14 ± 0.13 (23.0) | 4.17 ± 0.04 (64.74) | 4.04 ± 0.15 (56.8) | −28.64 ± 3.31 | 8.22 ± 0.12 (3714.5) | 0.83 ± 0.07 (2.29) | 4.96 ± 0.07 (142.6) |
| Test | na | 37.24 < 0.0001 | 29.22 < 0.0001 | 120.21 < 0.0001 | 1.10 < 0.2940 | 22.67 < 0.0001 | 18.07 < 0.0001 | 98.91 < 0.0001 |
| Grain + forage legume | 4.13 ± 0.04 (67.2) | 3.48 ± 0.58 (32.5) | 4.29 ± 0.08 (73.0) | 4.01 ± 0.17 (55.1) | −8.66 ± 19.99 | 8.12 ± 0.11 (3361.0) | 0.19 ± 0.19 (1.21) | 4.32 ± 0.18 (75.2) |
| Grain + forage | 3.95 ± 0.05 (49.4) | 2.48 ± 0.60 (11.9) | 4.03 ± 0.09 (56.3) | 4.25 ± 0.18 (70.1) | −57.78 ± 20.65 | 8.35 ± 0.12 (4230.2) | 0.92 ± 0.22 (2.51) | 5.05 ± 0.21 (156.0) |
| Test | 14.69 < 0.0001 | 8.68 < 0.0032 | 17.52 < 0.0001 | 17.11 < 0.0001 | 45.03 < 0.0001 | 14.81 < 0.0001 | 26.84 < 0.0001 | 26.12 < 0.0001 |
F statistics and probability values obtained from analysis of variance are given in italics, non-italicized text are means ± standard errors. All data are log-transformed with the exception of N surplus, back transformed mean values are included in brackets. “NUE,” denotes nutrient use efficiency, and “BOE,” biomass output efficiency.