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 Verchot, L. V. Articles by Gilliam, J. W. Search for Related Content PubMed Articles by Verchot, L. V. Articles by Gilliam, J. W. Agricola Articles by Verchot, L. V. Articles by Gilliam, J. W.

Nitrogen Cycling in Piedmont Vegetated Filter Zones: II. Subsurface Nitrate Removal

Woods Hole Res. Ctr., P.O. Box 296, Woods Hole, MA 02543;

E. Carlyle Franklin^*

Forestry Dep., Box 8006 North Carolina State Univ., Raleigh, NC 27695-8006;

J. Wendell Gilliam

Soils Dep., Box 7619, North Carolina State Univ., Raleigh, NC 27695-7619.

^* Corresponding author. (lvwhrc{at}mcimail.com).

ABSTRACT

Subsurface flow often constitutes the major pathway for movement of dissolved nutrients such as NO₃-N from agricultural fields. The objectives of this study were (i) to determine the changes in shallow groundwater chemistry along a piezometric gradient from agricultural fields, across grass-vegetated field edges and through adjacent forest on two Piedmont watersheds and (ii) determine the relative importance of dilution, denitrification, and plant uptake in subsurface NO₃ attenuation. We monitored changes in groundwater chemistry at three depths along a piezometric gradient from an agricultural field through a grass field edge and through a forested filter zone (FFZ). We measured marked decrease in nitrate concentrations from 8 to 10 mg L^–1 at the field edge to almost 0 at the forest edge; Cl concentrations remained within the range of 8 to 10 mg L^–1, suggesting that dilution was not an important factor in NO₃ concentration reductions. At a third site, we introduced NO₃-N and a conservative tracer, bromide, into the soil profile at both the grass-vegetated field border and the forested area, to determine mechanisms responsible for the observed decrease in NO₃-N concentrations. Using ion concentration ratios we determined that nitrate attenuation in the grass-vegetated field edge was low compared to the forest. Nitrate loss in the forest was almost exclusively through denitrification; plant uptake was insignificant in these experiments. Although grass-vegetated field borders were less effective than riparian forests at NO₃-N removal, considerable reductions were observed in these areas on the experimental watersheds. Similar reductions would be expected over shorter distances in riparian forests.

This article has been cited by other articles:

				A. R. Hill, P. G. F. Vidon, and J. Langat Denitrification Potential in Relation to Lithology in Five Headwater Riparian Zones J. Environ. Qual., May 1, 2004; 33(3): 911 - 919. [Abstract] [Full Text] [PDF]

				A. R. Hill and M. Cardaci Denitrification and Organic Carbon Availability in Riparian Wetland Soils and Subsurface Sediments Soil Sci. Soc. Am. J., January 1, 2004; 68(1): 320 - 325. [Abstract] [Full Text] [PDF]

				K. Addy, D. Q. Kellogg, A. J. Gold, P. M. Groffman, G. Ferendo, and C. Sawyer In Situ Push-Pull Method to Determine Ground Water Denitrification in Riparian Zones J. Environ. Qual., May 1, 2002; 31(3): 1017 - 1024. [Abstract] [Full Text] [PDF]

				D. L. Dinnes, D. L. Karlen, D. B. Jaynes, T. C. Kaspar, J. L. Hatfield, T. S. Colvin, and C. A. Cambardella Nitrogen Management Strategies to Reduce Nitrate Leaching in Tile-Drained Midwestern Soils Agron. J., January 1, 2002; 94(1): 153 - 171. [Abstract] [Full Text] [PDF]

				S.M. Meding, L. A. Morris, C. M. Hoover, W. L. Nutter, and M. L. Cabrera Denitrification at a Long-Term Forested Land Treatment System in the Piedmont of Georgia J. Environ. Qual., July 1, 2001; 30(4): 1411 - 1420. [Abstract] [Full Text] [PDF]

				T. E. Davidsson and M. Ståhl The Influence of Organic Carbon on Nitrogen Transformations in Five Wetland Soils Soil Sci. Soc. Am. J., May 1, 2000; 64(3): 1129 - 1136. [Abstract] [Full Text]