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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Bettany, J. R. Articles by Stewart, J. W. B. Search for Related Content PubMed Articles by Bettany, J. R. Articles by Stewart, J. W. B. Agricola Articles by Bettany, J. R. Articles by Stewart, J. W. B.

Comparison of the Amounts and Forms of Sulfur in Soil Organic Matter Fractions after 65 Years of Cultivation¹

ABSTRACT

Large differences in organic matter contents of a Udic Haploboroll soil were observed in the A horizons of adjacent cultivated (for 65 years) and permanent pasture sites. Relatively lower net losses of S (38%) comared to C (44%) and N (49%) and narrower C/N/S ratios indicated that S is more resistant to mineralization during cultivation processes than C and N. Organic S concentrations were lower in all 6 fractions obtained from a 0.1M NaOH-0.1M Na₄P₂O₇ (pH 13.0) extraction separation but differences were noted in absolute amounts and relative proportions of C, N and S lost from specific fractions. Three fractions, conventional humic acid (HA-A), clay associated humic acid (HA-B) and humin (<2 µm), accounted for 80% of the total S difference. In contrast, the fulvic acid (FA-A) fraction which had narrower C/N/S ratios, contained more HI-reducible S and was thought to be more labile than other fractions, only contributed 14% of the total S loss.

It was postulated that the breakdown and oxidation of HA-A, HA-B and humin <2-µm fractions during mineralization would liberate low molecular weight S compounds which would temporarily accumulate in FA-A fractions thereby accounting for a small net decrease in total S and a high percentage of HI-reducible S in this fraction in the cultivated soil.

¹ Journal Paper no. R234 of the Saskatchewan Institute of Pedology, University of Saskatchewan, Saskatoon, Sask. Research supported by the Sulphur Development Institute of Canada (SUDIC), the National Research Council of Canada Grant no. A4474, and the Canadian Commonwealth Scholarship and Fellowship Committee.

² Associate Professor, Research Assistant, and Professor of Soil Science, respectively, University of Saskatchewan, Saskatoon, Sask., Canada.

Received for publication May 29, 1979. Accepted for publication September 18, 1979.

This article has been cited by other articles:

				D. Solomon, J. Lehmann, and C. E. Martinez Sulfur K-edge XANES Spectroscopy as a Tool for Understanding Sulfur Dynamics in Soil Organic Matter Soil Sci. Soc. Am. J., November 1, 2003; 67(6): 1721 - 1731. [Abstract] [Full Text] [PDF]