Upland acid sulfate soils and the effect of sulfide oxidation on soil genesis in Saskatchewan soils, Canada
Recent studies on upland acid sulfate soils in east central Saskatchewan generated interest in further study of sulfide oxidation and its effect on soil salinity, soil acidity, Solonetzic soil formation and other soil properties. The objective of this study was to understand the effects of sulfide oxidation on soil properties, especially the formation of sulfate salts using chemical, x-ray diffraction and scanning electron microscope techniques. Field and laboratory studies indicated that pyrite and jarosite were also widespread occurrences in southern Saskatchewan. Extremely high concentration of sulfate salts (mirabilite, thenardite, bloedite, konyaite, loeweite, gypsum) were found in the depressions where the sulfide oxidation process was dominant in the subsoils. Presence of Solonetzic soils in higher elevations suggests their association to saline soils. Sulfide oxidation are likely responsible for most of the free iron oxides and iron substitution in smectites in Saskatchewan soils.
Soils and Crops Workshop