ISSN:
1365-2389
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Intense decalcification of fine-grained organic-rich soils subject to periodic oxidation and reduction takes place in the Biesbosch, a freshwater, tidally influenced wetland area in the Rhine–Meuse delta in The Netherlands. Soil chemical (sulphide concentration and pore-water characteristics) and hydrological variables (drainage) were measured in three representative Fluvisols differing in hydrology to identify processes inducing calcium carbonate dissolution. Both oxidation of previously formed iron sulphides during periods of low ground water and infrequent inundation, and increased carbon dioxide pressure in the soil during periods of waterlogging combined with drainage of pore-water solutes, contribute significantly to decalcification of the hydric soils. The effects of these individual processes on decalcification are in the same order of magnitude in the studied soils. Depending on site-specific hydrological conditions, approximately 0.1–0.3% calcium carbonate may be dissolved per year by a combination of these two processes, which is comparable to actual decalcification rates at these sites. Estimates of long-term decalcification rates, based on knowledge of the hydrogeochemistry, may be used to assess the risks accompanying the conversion of agricultural soils into wetlands.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2389.2000.00279.x
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