HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Clayton, J. L. Articles by Nagel, T. Search for Related Content PubMed Articles by Clayton, J. L. Articles by Nagel, T. Agricola Articles by Clayton, J. L. Articles by Nagel, T.

Soil Response to Acid Deposition, Wind River Mountains, Wyoming: II. Column Leaching Studies

Forestry Sciences Lab., Boise, ID 83702

Terry Nagel

College of Idaho, Caldwell, ID

*Corresponding author.

ABSTRACT

Both base exchange and SO₄ adsorption were important proton consuming processes in a laboratory leaching study of western, high-elevation Inceptisols. Two soils formed from granitic parent materials are present in the watershed: a highly organic Humic Cryaquept (HCA) located adjacent to streams and on lake margins, and an upland Dystric Cryochrept (DCO). Large, single-horizon soil columns were leached sequentially with deionized H₂O (six pore volumes [PV]), pH 4 H₂SO₄ (12–16 PVs), and pH 3 H₂SO₄ (11–16 PVs). These treatments were equivalent to 3 to 6 yr of runoff and 50 to 100 times annual S-deposition rates. Proton exchange for base cations was very effective at buffering all horizons for the distilled H₂O and pH 4 treatments. Following three to five PVs of pH 3 H₂SO₄, leachate pH dropped to 5 in the B horizon and 4.2 in the C horizon of the DCO. The Al(OH)₃ dissolution then stabilized the pH in those two experiments. The A horizon of the DCO and both HCA horizons had sufficient cation-exchange capacity (CEC) and base saturation to resist large pH depressions during the pH 3 treatment. Cation exchange was the dominant neutralization process, accounting for 56 to 96% of total proton consumption. Sulfate adsorption was important in DCO horizons (20–35% of protons consumed), but not in the organic HCA soil. Postleaching analysis of soils indicated that exchangeable Na and Mg decreased to about one-half of original values, but Ca and K remained unchanged. Apparently, hydrolysis of abundant primary minerals can resupply these cations under the conditions of these experiments.

Contribution from the Intermountain Res. Stn., U.S. Forest Service, Ogden, UT 84401.

Received for publication October 15, 1990.