Table 2 Variation of soil CH4 concentrations (μL L-1) averaged for with soil depth (SD) at the jointing, heading, and filling stages of wheat growth period under the fertilization levels of 75% (75% NF), 100% (NF) and 125% (125% NF) of the normal fertilizer application rate and the groundwater depths (GD) of 20, 40, 50, 60, and 80 cm. The values shown are the means of three replicates ± standard deviations. Within a treatment, the means followed by different lowercase letters are significantly different atP ≤ 0.05 as determined by the LSD test
Table 3 ANOVA statistical significance of between-subject effects and within-subject effects for groundwater depth (GD) and fertilization levels (FL) on soil CO2 and CH4 concentrations, root parameters, shoot biomass, and root-shoot ratio. *, **, and *** indicate statistical significance respectively at 0.05, 0.01, and 0.001 probability levels; NS indicates no significance at 0.05 statistical level