Flux of COS, DMS and CS₂ from various soils in Germany

Abstract

Emission rates of the reduced sulfur gases carbonyl sulfide (COS), dimethyl sulfide (CH₃SCH₃) and carbon disulfide (CS₂) from 12 representative soils in Germany have been examined by means of a dynamic gas emission chamber. The compounds were sampled by cryogenic technique and measured by subsequent GC/FPD-analysis. It could be shown that besides soil type, soil temperature and moisture are the major factors controlling source strength. DMS and COS were the predominant gases emitted from organic soils; CS₂ emission rates showed highest values at waterlogged soils. Measurements of the diurnal variations of emission rates show daily patterns of DMS and COS emission rates which coincide with the soil temperature curve, whereas the CS₂ emission showing a maximum at midday might be determined by other factors, e.g., light intensity. Seasonal changes in the physiology of plants and in the population of soil micro-organisms may cause the measured peak emissions during fall at comparatively low soil temperatures.