Sulfate Reduction Rates in Louisiana Marsh Soils

2 Sulfate Reduction Rates in Louisiana Marsh Soils 

Potential sulfate reduction rates for three Louisiana marsh soils of varying salinities (salt, brackish, and freshwater) have been determined (DeLanne et al., 2002a). The three Louisiana marshes represent different physiochemical environments. The fresh and brackish marsh soils are composed predominantly of organic matter, whereas the salt marsh soils are higher in mineral matter. Sulfate content is higher in the salt marsh. 

The brackish and fresh marshes contain similar sulfate contents, although means were higher in the brackish marsh. Average potential sulfate reduction rates over three sampling periods (Angnst, December, and April) were 45.9, 40, and 33.4 mol S m year respectively, for fresh, brackish, and salt marsh (Table 18.12). Turnover times are consistently longer in the salt marsh (approximately 40 days, Fignre 18.23) than in either the fresh or the brackish marshes (3-8 days). 

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