The effect of elemental sulfur on certain chemical and biological properties of surface organic horizons of a forest soil

Abstract

Elemental sulfur is a by-product of sour natural gas processing in Alberta, Canada. Breakup and weathering of the storage elemental sulfur blocks has resulted in the deposition of large amounts of elemental sulfur into adjacent forest ecosystems. This has caused considerable damage to the understory vegetation. Certain chemical and biological properties of surface organic forests horizons (LFH) that have been exposed to elemental sulfur for several years were examined over a 2-year period. Increasing concentrations of elemental sulfur (4 100 to 50 400 mg S kg soil−1) and 1.0 M NH4Cl extractable S and decreasing pH (4.4 to 2.4) occurred in the LFH with increasing proximity (750, 250, and 50 m) to the elemental sulfur source. Thiobacillusthiooxidans appeared to be the main organism responsible for elemental sulfur oxidation in all LFH samples. The site immediately adjacent to the elemental sulfur block (50 m) showed reduced concentrations of total and 1.0 M NH4Cl extractable Ca, Mg, K, and Mn. In addition, in the 2nd year of sampling, CO2 respiration in nonamended and glucose-amended samples was significantly reduced. The other sites (250 and 750 m from the block) showed no significant decrease in nutrient status or heterotrophic microbial activity.