Table 2.
Soil CH4 flux in different N rates (mean ± SE) and two-way ANOVA for soil CH4 fluxes in response to N rates, year and their interaction.
| Year | T1 | T2 | T3 | T4 | Average |
|---|---|---|---|---|---|
| (µg C m− 2 hr− 1) | |||||
| 2010 | 90.2 ± 13.4 | 110.0 ± 11.5 | 77.2 ± 17.9 | 68.6 ± 11.0 | 86.5 ± 9.0 |
| 2011 | 65.8 ± 13.3 | 49.4 ± 18.4 | 52.1 ± 6.6 | 64.1 ± 14.2 | 57.9 ± 4.1 |
| 2012 | 66.2 ± 17.2 | 74.4 ± 19.6 | 39.5 ± 18.7 | 42.2 ± 16.8 | 55.6 ± 8.7 |
| 2013 | 22.7 ± 14.5 | 23.5 ± 14.9 | 19.5 ± 9.5 | 32.4 ± 17.6 | 24.5 ± 2.8 |
| 2016 | 40.6 ± 18.8 | 50.1 ± 17.3 | 51.9 ± 27.7 | 59.1 ± 15.4 | 50.4 ± 3.8 |
| 2017 | 68.8 ± 41.2 | 78.9 ± 29.8 | 67.2 ± 29.6 | 57.7 ± 29.2 | 68.1 ± 4.4 |
| Mean | 59.1 ± 9.7 | 64.4 ± 12.2 | 3.96 ± 8.3 | 4.21 ± 5.6 | |
| Source | d.f | Mean Square | F-value | p-value | |
|---|---|---|---|---|---|
| Year | 5 | 20092.91 | 4.17 | 0.001 | |
| N rates | 3 | 2427.35 | 0.50 | 0.680 | |
| Year * N rates | 15 | 1576.37 | 0.33 | 0.992 | |
| Error | 264 | 4818.46 | |||
d.f. = degrees of freedom; F-value = ratio of between-group variance to within-group variance; p-value = the statistical significance of the test result. Significance at p < 0.05.