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 Gupte, S. M. Articles by Hendrix, P. F. Search for Related Content PubMed Articles by Gupte, S. M. Articles by Hendrix, P. F. Agricola Articles by Gupte, S. M. Articles by Hendrix, P. F.

Anion Transport in a Piedmont Ultisol: II. Local-Scale Parameters

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

E. W. Tollner

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

P. F. Hendrix

Inst. of Ecology, Univ. of Georgia, Athens, GA.

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

ABSTRACT

Field-scale transport parameters obtained from tile drain data in two large conventionally tilled plots were reported in the first paper in this series. Our objectives in this paper were to determine the relationship between local-scale transport parameters and macropore distributions measured with columns in one of these plots and to compare local-scale transport parameters with the field-scale parameters. Forty undisturbed soil columns (15 cm in diameter, 33–64 cm in length) were taken from Plot 1 described in the first paper. Transport parameters were determined from a Br breakthrough curve (BTC) with CXTFIT. Macropore distributions were determined from computed tomography (CT) scanning and by sectioning the columns after adding methylene blue dye. Local-scale saturated hydraulic conductivity (K_s), pore water velocity (V), and dispersivity () were highly variable (coefficient of variation of 77, 74, and 41%, respectively) and lognormally distributed. The K_s was positively correlated with the number of 5- to 10-mm-diameter CT scan macropores at a depth of 35 to 40 cm near the top of the Bt horizon. Dye patterns indicated that preferential flow began at about this depth. This may be the zone where flow becomes restricted and highly dependent on macropores. Mean local-scale (6.6 cm) was similar to the estimated field-scale values (3.4 and 5.3 cm) for the unsaturated zone to a depth of 20 cm. This implied that variation among local-scale V in the field experiment was much less than that observed in the columns, probably because the surface was not ponded in the field. A deterministic approach with mean values of local-scale parameters adequately described the estimated field-scale BTC.

Received for publication October 31, 1994.

This article has been cited by other articles:

				D. A. Abrahamson, D. E. Radcliffe, J. L. Steiner, M. L. Cabrera, D. M. Endale, and G. Hoogenboom Evaluation of the RZWQM for Simulating Tile Drainage and Leached Nitrate in the Georgia Piedmont Agron. J., May 3, 2006; 98(3): 644 - 654. [Abstract] [Full Text] [PDF]

				A. Gaur, R. Horton, D. B. Jaynes, and J. L. Baker Measured and Predicted Solute Transport in a Tile Drained Field Soil Sci. Soc. Am. J., April 19, 2006; 70(3): 872 - 881. [Abstract] [Full Text] [PDF]

				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]

				K. A. McVay, D. E. Radcliffe, L. T. West, and M. L. Cabrera Anion Exchange in Saprolite Vadose Zone J., May 1, 2004; 3(2): 668 - 675. [Abstract] [Full Text] [PDF]

				J.N. Shaw, L.T. West, D.E. Radcliffe, and D.D. Bosch Preferential Flow and Pedotransfer Functions for Transport Properties in Sandy Kandiudults Soil Sci. Soc. Am. J., March 1, 2000; 64(2): 670 - 678. [Abstract] [Full Text]

				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]