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 Radcliffe, D. E. Articles by Tollner, E. W. Search for Related Content PubMed Articles by Radcliffe, D. E. Articles by Tollner, E. W. Agricola Articles by Radcliffe, D. E. Articles by Tollner, E. W.

Anion Transport in a Piedmont Ultisol: I. Field-Scale Parameters

Dep. of Crop and Soil Sciences, Univ. of Georgia, Athens, GA 30602

P. M. Tillotson

Dupont Agricultural Products, Wilington, DE 19880-0402

J. E. Box

USDA-ARS, Southern Piedmont Conservation Research Center, Watkinsville, GA 30677

E. W. Tollner

Dep. of Agricultural and Biological Engineering, Univ. of Georgia, Athens, GA.

*Corresponding author (dradclif{at}uga.cc.uga.edu).

ABSTRACT

Tile drains have been suggested as a method of measuring field-scale transport parameters, but lateral flow to the drains in the saturated zone can introduce error in the measurement of unsaturated zone parameters. Our objective was to use a two-layer transfer function model to determine field-scale unsaturated zone transport parameters from tile drain breakthrough curves measured in two 12.5 by 30.5 m plots. Plots were irrigated to steady-state tile drain flow, Cl was added as a tracer, and irrigation was continued for up to 600 h. The first layer of the transfer function model consisted of the unsaturated zone and was described by the convection-dispersion equation (CDE) probability density function (pdf). The second layer consisted of the saturated zone and was described by the gamma distribution pdf. The CDE parameters were determined from a fit of the two layer model to the drainage pdf in each tile drain. Transport parameters were similar for the two plots. Mean field-scale dispersivity () for the unsaturated zone (0–20 cm) was 5.3 cm for Plot 1 and 3.4 cm for Plot 2. This was much less than calculated for the overall system by moment analysis ( = 23.7 and 19.5 cm in Plot 1 and 2, respectively) suggesting that most of the dispersion of the tile drain breakthrough curves was due to lateral flow in the saturated zone. This illustrates that tile drain breakthrough curves can be used to determine field-scale unsaturated zone transport parameters provided a model is used that accounts for two-dimensional flow in the saturated zone.

Received for publication December 2, 1993.

This article has been cited by other articles:

				D. A. Abrahamson, D. E. Radcliffe, J. L. Steiner, M. L. Cabrera, J. D. Hanson, K. W. Rojas, H. H. Schomberg, D. S. Fisher, L. Schwartz, and G. Hoogenboom Calibration of the Root Zone Water Quality Model for Simulating Tile Drainage and Leached Nitrate in the Georgia Piedmont Agron. J., November 17, 2005; 97(6): 1584 - 1602. [Abstract] [Full Text] [PDF]

				D. E. Radcliffe, L. T. West, and J. Singer Gravel Effect on Wastewater Infiltration from Septic System Trenches Soil Sci. Soc. Am. J., June 28, 2005; 69(4): 1217 - 1224. [Abstract] [Full Text] [PDF]

				T. J. Gish, K.-J. S. Kung, D. C. Perry, J. Posner, G. Bubenzer, C. S. Helling, E. J. Kladivko, and T. S. Steenhuis Impact of Preferential Flow at Varying Irrigation Rates by Quantifying Mass Fluxes J. Environ. Qual., May 1, 2004; 33(3): 1033 - 1040. [Abstract] [Full Text] [PDF]

				K.R. Wythers, W.K. Lauenroth, and J.M. Paruelo Bare-Soil Evaporation Under Semiarid Field Conditions Soil Sci. Soc. Am. J., September 1, 1999; 63(5): 1341 - 1349. [Abstract] [Full Text]

				A. D. Johnson, M. L. Cabrera, D. V. McCracken, and D. E. Radcliffe LEACHN Simulations of Nitrogen Dynamics and Water Drainage in an Ultisol Agron. J., July 1, 1999; 91(4): 597 - 606. [Abstract] [Full Text] [PDF]