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 Sharpley, A. N. Search for Related Content PubMed Articles by Sharpley, A. N. Agricola Articles by Sharpley, A. N.

Kinetics of Sulfate Desorption from Soil

USDA-ARS Water Quality and Watershed Research Lab., P.O. Box 1430, Durant, OK 74702-1430

*Corresponding author.

ABSTRACT

Sulfate desorption and mobility in soil can be of both environmental and agronomic importance. This study was conducted to describe the desorption of SO₄ from agricultural soils under experimental conditions applicable to the movement of SO₄ in overland flow and runoff waters. The kinetics of SO₄ desorption from soil were investigated at five different water/soil ratios (10:1–400:1), five time periods (5–180 min), and four SO₄ additions (0–200 mg kg^–1). Sulfate desorption (S_d) was logarithmically related to contact time (t) and water/soil ratio (W) and was a linear function of the initial extractable SO₄ content of soil (S_e). The kinetics of SO₄ desorption was described by the equation S_d = K S_e t W^ß, where K, , and ß are constants for a given soil. This equation has previously been shown to describe desorption of soil P and K. The kinetic constants, K (r² = 0.88), (r² = 0.83), and ß (r² = 0.88), were related to extractable soil Al content for 107 U.S. soils. The uniformity of equation constants for a given soil and the ease with which they can be estimated from extractable soil Al indicate the potential use of the equation in modeling SO₄ desorption from soil and subsequent movement in surface runoff water.

Received for publication January 16, 1990.