Interference by organic complexation of Fe and A1 on the SO2-4 adsorption in Spodic B horizons in Sweden

Abstract

The relations between pH, different fractions of Fe and Al and Na4P2O7-soluble C and the amount of adsorbed SO42- were assessed by analysing 63 soil samples from 14 podsolized soils in Sweden. The amount of adsorbed SO42- was significantly better correlated with the calculated amount of the inorganic fraction of Fe and Al oxides obtained by subtracting Na4P2O7-soluble Fe and Al from oxalate-soluble Fe and Al than with the oxalate extraction alone. There was a close correlation between C and organically-bound S in the Na4P2O7 extract which shows that the C:S ratio of the extracted fulvic acids is about constant in the soils studied. It was found that, as the proportion of organically-complexed Fe and Al increases, the ability of the soil to adsorb SO42- decreases. The amount of adsorbed SO42- expressed on the basis of the amounts of oxalate-soluble Fe and Al was generally smaller in areas with low S deposition (<60 mmol m-2 a-1). The ratio between pyrophosphate-soluble C and oxalate-extractable Fe and Al was negatively correlated with pH in water. It was concluded that Fe and Al associated with organic matter cannot adsorb SO42- and that the degree of this association is pH dependent. These observations have important implications regarding the effects of anthropogenic acidification.

Published in

Journal Of Soil Sciences
1993, volume: 44, number: 4, pages: 625-632
Publisher: BLACKWELL SCIENCE LTD

SLU Authors

• Karltun, Erik

  • Department of Soil Sciences, Swedish University of Agricultural Sciences
    

• Gustafsson, Jon-Petter

  • Royal Institute of Technology (KTH)

UKÄ Subject classification

Soil Science

Publication identifier

• DOI: https://doi.org/10.1111/j.1365-2389.1993.tb02327.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/69511