Table 2.
Summary of ANOVA results for effects of elevated CO2 and increased nitrogen fertilization on chemical components of maize.
| Measurement | Treatment | df | F | P |
|---|---|---|---|---|
| Starch | CO2 | 1 | 10 | 0.01 |
| N | 2 | 23.2 | <0.01 | |
| CO2∗N | 2 | 0.24 | 0.80 | |
| Soluble sugar | CO2 | 1 | 0.16 | 0.70 |
| N | 2 | 1.71 | 0.24 | |
| CO2∗N | 2 | 1.8 | 0.23 | |
| Nitrogen | CO2 | 1 | 3.15 | 0.11 |
| N | 2 | 17.83 | <0.01 | |
| CO2∗N | 2 | 16.83 | <0.01 | |
| TNC/N | CO2 | 1 | 0.11 | 0.75 |
| N | 2 | 1.47 | 0.29 | |
| CO2∗N | 2 | 10.45 | <0.01 |
∗TNC, total non-structural carbohydrates; N, low N fertilization level (100 mg N/kg soil mixture), middle N fertilization level (200 mg N/kg soil mixture) and high N fertilization level (300 mg N/kg soil mixture); CO2, ambient CO2 concentrations (∼380 ppm) and elevated CO2 concentrations (∼750 ± 15 ppm); n = 3.