Emission of biogenic sulfur gases from Chinese rice paddies

Biogenic sulfur gases emitted from Chinese rice paddies were measured with a laboratory incubation and a closed chamber method in the field. Six speciations of sulfur-containing gases were detected in both conditions: hydrogen sulfide (H2S), carbonyl sulfide (COS), methyl mercaptan (CH3SH), carbon disulfide (CS2), dimethyl sulfide (CH3SCH3 or DMS) and dimethyl disulfide (CH3SSCH3 or DMDS). Among them, DMS comprised the major part of the sulfur emission. Emission of sulfur gases from different paddy soils exhibit high spatial and temporal variability. The emission of volatile sulfur gases increased with application of organic manure and positively correlated with the total sulfur content in the soil. The diurnal and seasonal variations of total volatile sulfur gases and DMS indicate that their emissions were greatly influenced by the air temperature and the activity of the rice plant. The annual emission of total volatile sulfur gases from the Nanjing rice paddy field ranged from 4.0 to 9.5 mg S m−2 year−1, that of DMS ranged from 3.1 to 6.5 mg S m−2 year−1.