Table 1.
Maize yield and N use efficiency in N fertilizer application treatments.
| Fertilizer Input (kg N ha−1) |
Maize Yield (kg ha−1) |
Soybean BNF (kg N ha−1) |
Soybean Harvest Export (kg N ha−1) |
Maize Aboveground Biomass N (kg N ha−1) |
Maize Harvest Export N (kg N ha−1) |
N surplusa (kg N ha−1) |
N Use Efficiencyb |
N Recovery efficiency (kg kg−1)c |
|---|---|---|---|---|---|---|---|---|
| 0 | 6,400a (400) |
217 | 184 | 115a (12.4) |
69a (5.6) |
−36a (5.6) |
1.17a (0.03) |
N.A. |
| 80 | 9,100ab (200) |
217 | 184 | 169a (11.5) |
104ab (3.2) |
9b (3.2) |
0.97b (0.01) |
0.68a (0.23) |
| 120 | 8,400b (900) |
217 | 184 | 177a (20.3) |
95ab (11.6) |
58c (12) |
0.83ce (0.03) |
0.51a (0.18) |
| 160 | 9,100b (900) |
217 | 184 | 210b (31.4) |
118b (15.5) |
75cd (16) |
0.80cd (0.04) |
0.59a (0.27) |
| 200 | 9,100b (300) |
217 | 184 | 198a (9.6) |
120b (5.4) |
113d (5.4) |
0.73de (0.01) |
0.42a (0.04) |
Treatments with different lettered superscripts differ significantly based on a post-hoc Tukey HSD test. Values in parentheses are standard errors.
aCalculated as inputs – exports. bCalculated as exports/inputs. cCalculated as (fertilized export – control export)/fertilizer input.