Abstract
The emissions of biogenic hydrogen sulfide (H₂S) and sulfur dioxide (SO₂) play important roles in the global atmospheric sulfur (S) cycle. Field-based investigations using ultraviolet fluorescence spectroscopy show that drained acid sulfate soils (ASS) are a potentially unaccounted source of biogenic H₂S and SO₂. Significant diurnal variations were evident in SO₂ fluxes, with average daytime measurements 9.3-16.5-fold greater than night-time emissions. Similar diurnal patterns in H₂S fluxes were observed but proved statistically insignificant. The results from simultaneously collected micrometeorological measurements suggest that emissions of SO₂ and H₂S are most likely occurring via different processes. The SO₂ fluxes are closely linked to surface soil temperature and moisture content, whereas H₂S is constantly emitted from the land surface at the two study sites. Drained ASS are most likely mapped as agricultural lands rather than drained backswamps. Therefore, these areas are likely to be assigned H₂S and SO₂ flux values of zero in greenhouse gas species inventories. These findings suggest a need to expand these measurements to other drained ASS areas to refine regional (and possibly global) atmospheric S budgets. Further research is necessary to elucidate the sources of measured S compounds, and specifically whether they are limited to individual agricultural drainage patterns in ASS.
Original language | English |
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Pages (from-to) | 471-480 |
Number of pages | 10 |
Journal | Soil Research |
Volume | 49 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2011 |
Keywords
- acid sulfate soils
- atmospheric sulfur compounds
- biogeochemistry
- diurnal variations
- fluorescence spectroscopy
- global warming
- hydrogen sulfide
- micrometeorology
- soil moisture
- subsurface drainage
- sulfur dioxide