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

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed 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 Mertens, J. Articles by Smolders, E. Search for Related Content PubMed PubMed Citation Articles by Mertens, J. Articles by Smolders, E. Agricola Articles by Mertens, J. Articles by Smolders, E. Related Collections Carbon Sequestration Field-Scale Studies Soil Hydrology

TECHNICAL REPORTS

Vadose Zone Processes and Chemical Transport

Dissolved Organic Carbon Fluxes under Bare Soil

^a Soil and Water Management, K.U. Leuven, Celestijnenlaan 200E, B-3001 Heverlee, Belgium
^b Agrosphere, ICG-IV, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany

^* Corresponding author (mertensja{at}yahoo.co.nz)

Received for publication September 14, 2006. The flux of dissolved organic carbon (DOC) in soil facilitates transport of nutrients and contaminants in soil. There is little information on DOC fluxes and the relationship between DOC concentration and water flux in agricultural soils. The DOC fluxes and concentrations were measured during 2.5 yr using 30 automatic equilibrium tension plate lysimeters (AETPLs) at 0.4 m and 30 AETPLs at 1.20-m depth in a bare luvisol, previously used as an arable soil. Average annual DOC fluxes of the 30 AETPLS were 4.9 g C m^–2 y^–1 at 0.4 m and 2.4 g C m^–2 y^–1 at 1.2 m depth. The average leachate DOC concentrations were 17 mg C L^–1 (0.4 m) and 9 mg C L^–1 (1.2 m). The DOC concentrations were unrelated to soil moisture content or average temperature and rarely dropped below 9 mg C L^–1 (0.4 m) and 5 mg C L^–1 (1.2 m). The variability in cumulative DOC fluxes among the plates was positively related to leachate volume and not to average DOC concentrations at both depths. This suggests that water fluxes are the main determinants of spatial variability in DOC fluxes. However, the largest DOC concentrations were inversely proportional to the mean water velocity between succeeding sampling periods, suggesting that the maximal net DOC mobilization rate in the topsoil is limited. Elevated DOC concentrations, up to 90 mg C L^–1, were only observed at low water velocities, reducing the risks of DOC-facilitated transport of contaminants to groundwater. The study emphasizes that water flux and velocity are important parameters for DOC fluxes and concentrations.

Abbreviations: AETPL, automatic equilibrium tension plate lysimeter • DOC, dissolved organic carbon

This article has been cited by other articles:

				Y. Liang, H. T. Gollany, R. W. Rickman, S. L. Albrecht, R. F. Follett, W. W. Wilhelm, J. M. Novak, and C. L. Douglas Jr. CQESTR Simulation of Management Practice Effects on Long-Term Soil Organic Carbon Soil Sci. Soc. Am. J., August 20, 2008; 72(5): 1486 - 1492. [Abstract] [Full Text] [PDF]

				J. Mertens, V. Tuts, J. Diels, J. Vanderborght, J. Feyen, and R. Merckx Design and Testing of a Drop Counter for Use in Vadose Zone Water Samplers Vadose Zone J., April 14, 2008; 7(2): 434 - 438. [Abstract] [Full Text] [PDF]