Relating Sulfate Adsorption to Soil Properties in Michigan Forest Soils
- Neil W. MacDonald and
- James B. Hart
Six Michigan forest soil series comprising several gradients in soil physical and chemical properties were studied to relate SO4 adsorption to soil properties. The series studied were Grayling (mixed, frigid Typic Udipsamments), Rubicon (sandy, mixed, frigid Entic Haplorthods), Kalkaska (sandy, mixed, frigid Typic Haplorthods), Montcalm (coarse-loamy, mixed Eutric Glossoboralfs), Spinks (sandy, mixed, mesic Psammentic Hapludalfs), and Oshtemo (coarse-loamy, mixed, mesic Typic Hapludalfs). Six randomly located map units of each series were sampled in the lower peninsula of Michigan. An index of SO4 adsorption potential was determined by shaking samples in solutions containing 0.312 mmol SO4-S L−1 and measuring the loss of SO4 from solution. The highest SO4-adsorption potentials were found in Bw, Bs, and Bhs horizons of the Grayling, Rubicon, Kalkaska, and Montcalm series (7.0 to 14.1 mg S kg−1) and in E and Bt horizons of the Spinks and Oshtemo series (4.3 to 10.1 mg S kg−1). Significant differences in adsorption among series were present when comparing the upper 50 cm or the 100- to 150-cm depths in subsurface horizons, related to differences in Al, Fe, and clay concentrations. Sulfate adsorption was positively correlated with dithionite-citrate and ammonium oxalate extractable Al concentrations in subsurface horizons of the soils studied (r = 0.69–0.90). Regression analyses indicated that SO4 adsorption could be predicted using variables derived from commonly measured soil properties (Al, Fe, pH, organic C, extractable P), with maximum R2 values ranging from 0.83 to 0.89.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .