Methane Production and Consumption in Loess Soil at Different Slope Position

Table 2

CH₄ production, CO₂ evolution and O₂ uptake of soils collected from three slope positions, and incubated for 28 days under flooding (average values ± standard error, 𝑛=3).

Slope position	Soil depth (cm)	CH4 production		CO2 evolution (mg C kg^−1)	O2 uptake % (v/v)
		Total (mg C kg^−1)	Rate (mg C kg^−1 d^−1)
Top	0–20	0.3595 ± 0.118	0.0316	138.1 ± 2.56	14.61 ± 0.85
	20–40	0.0017 ± 0.001	0.0001	110.2 ± 2.19	8.73 ± 0.04
Middle	0–20	3.1679*** ± 0.140	0.3042	207.6*** ± 2.34	19.14** ± 0.10
	20–40	1.3538*** ± 0.129	0.1162	174.6*** ± 0.48	18.49*** ± 0.29
Bottom	0–20	0.0584 ns ± 0.011	0.0065	106.7** ± 0.13	11.65** ± 0.12
	20–40	0.0018 ns ± 0.001	0.0003	47.8*** ± 0.59	7.71 ns ± 0.13

*, **, ***, different from the Top position (reference soil) at 𝑃<0.05, 𝑃<0.01 and 𝑃<0.001, respectively, according to Student’s t-test; ns—not significant difference.