Column tracer studies in surface and subsurface horizons of two typic argiudolls

Francisco Bedmar, José Luis Costa, Daniel Gimenez

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Soil properties that vary in space and/or time within a soil profile introduce heterogeneity to solute transport. The objectives of this work were to (i) study transport of bromide through the horizons of two soils under no-tillage but differing in soil structure and organic carbon content, and (ii) determine the nature of the process by fitting breakthrough curves (BTC) with a convection-dispersion model assuming equilibrium (CDEeq) and nonequilibrium (CDEneq). Three sets of undisturbed soil cores were collected from the A, B, and C horizons of two soils and used to independently measure BTC of bromide, water retention (Tempe cells and pressure extractors), and saturated hydraulic conductivity (constant head). Data were fitted with the deterministic models CDEeq and CDEneq as implemented in CXTFIT version 2.1 and used to estimate pore water velocity (v) and hydrodynamic dispersion (D). The shape of BTC of horizons A and B exhibited tailing, asymmetry, and early appearance of the tracer, but there was no statistical difference between the goodness-of-fit of the CDEeq and CDEneq models. Values of v, D, and dispersivity (λ), indicated that flow in the A and B horizons were dominated by convection and dispersion, whereas the prevalent transport mechanism in C horizons was convection. Values of λ were significantly correlated (r = 0.83; P < 0.05) to clay content mainly because of the correlation between clay and the dispersion coefficients D estimated with either model. Transport properties of soil horizons should be considered when modeling nonreactive solute transport for assessing risks of groundwater contamination.

Original languageEnglish (US)
Pages (from-to)237-247
Number of pages11
JournalSoil Science
Volume173
Issue number4
DOIs
StatePublished - Apr 1 2008

Fingerprint

Argiudolls
tracer techniques
tracer
convection
breakthrough curve
C horizons
soil transport processes
solute transport
B horizons
bromide
A horizons
bromides
clay
hydrodynamic dispersion
dispersivity
soil
zero tillage
extractors
soil horizon
water retention

All Science Journal Classification (ASJC) codes

  • Soil Science

Cite this

Bedmar, Francisco ; Costa, José Luis ; Gimenez, Daniel. / Column tracer studies in surface and subsurface horizons of two typic argiudolls. In: Soil Science. 2008 ; Vol. 173, No. 4. pp. 237-247.
@article{5eac955e67d24edb945f8a0451794727,
title = "Column tracer studies in surface and subsurface horizons of two typic argiudolls",
abstract = "Soil properties that vary in space and/or time within a soil profile introduce heterogeneity to solute transport. The objectives of this work were to (i) study transport of bromide through the horizons of two soils under no-tillage but differing in soil structure and organic carbon content, and (ii) determine the nature of the process by fitting breakthrough curves (BTC) with a convection-dispersion model assuming equilibrium (CDEeq) and nonequilibrium (CDEneq). Three sets of undisturbed soil cores were collected from the A, B, and C horizons of two soils and used to independently measure BTC of bromide, water retention (Tempe cells and pressure extractors), and saturated hydraulic conductivity (constant head). Data were fitted with the deterministic models CDEeq and CDEneq as implemented in CXTFIT version 2.1 and used to estimate pore water velocity (v) and hydrodynamic dispersion (D). The shape of BTC of horizons A and B exhibited tailing, asymmetry, and early appearance of the tracer, but there was no statistical difference between the goodness-of-fit of the CDEeq and CDEneq models. Values of v, D, and dispersivity (λ), indicated that flow in the A and B horizons were dominated by convection and dispersion, whereas the prevalent transport mechanism in C horizons was convection. Values of λ were significantly correlated (r = 0.83; P < 0.05) to clay content mainly because of the correlation between clay and the dispersion coefficients D estimated with either model. Transport properties of soil horizons should be considered when modeling nonreactive solute transport for assessing risks of groundwater contamination.",
author = "Francisco Bedmar and Costa, {Jos{\'e} Luis} and Daniel Gimenez",
year = "2008",
month = "4",
day = "1",
doi = "10.1097/SS.0b013e31816a1e42",
language = "English (US)",
volume = "173",
pages = "237--247",
journal = "Soil Science",
issn = "0038-075X",
publisher = "Lippincott Williams and Wilkins",
number = "4",

}

Column tracer studies in surface and subsurface horizons of two typic argiudolls. / Bedmar, Francisco; Costa, José Luis; Gimenez, Daniel.

In: Soil Science, Vol. 173, No. 4, 01.04.2008, p. 237-247.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Column tracer studies in surface and subsurface horizons of two typic argiudolls

AU - Bedmar, Francisco

AU - Costa, José Luis

AU - Gimenez, Daniel

PY - 2008/4/1

Y1 - 2008/4/1

N2 - Soil properties that vary in space and/or time within a soil profile introduce heterogeneity to solute transport. The objectives of this work were to (i) study transport of bromide through the horizons of two soils under no-tillage but differing in soil structure and organic carbon content, and (ii) determine the nature of the process by fitting breakthrough curves (BTC) with a convection-dispersion model assuming equilibrium (CDEeq) and nonequilibrium (CDEneq). Three sets of undisturbed soil cores were collected from the A, B, and C horizons of two soils and used to independently measure BTC of bromide, water retention (Tempe cells and pressure extractors), and saturated hydraulic conductivity (constant head). Data were fitted with the deterministic models CDEeq and CDEneq as implemented in CXTFIT version 2.1 and used to estimate pore water velocity (v) and hydrodynamic dispersion (D). The shape of BTC of horizons A and B exhibited tailing, asymmetry, and early appearance of the tracer, but there was no statistical difference between the goodness-of-fit of the CDEeq and CDEneq models. Values of v, D, and dispersivity (λ), indicated that flow in the A and B horizons were dominated by convection and dispersion, whereas the prevalent transport mechanism in C horizons was convection. Values of λ were significantly correlated (r = 0.83; P < 0.05) to clay content mainly because of the correlation between clay and the dispersion coefficients D estimated with either model. Transport properties of soil horizons should be considered when modeling nonreactive solute transport for assessing risks of groundwater contamination.

AB - Soil properties that vary in space and/or time within a soil profile introduce heterogeneity to solute transport. The objectives of this work were to (i) study transport of bromide through the horizons of two soils under no-tillage but differing in soil structure and organic carbon content, and (ii) determine the nature of the process by fitting breakthrough curves (BTC) with a convection-dispersion model assuming equilibrium (CDEeq) and nonequilibrium (CDEneq). Three sets of undisturbed soil cores were collected from the A, B, and C horizons of two soils and used to independently measure BTC of bromide, water retention (Tempe cells and pressure extractors), and saturated hydraulic conductivity (constant head). Data were fitted with the deterministic models CDEeq and CDEneq as implemented in CXTFIT version 2.1 and used to estimate pore water velocity (v) and hydrodynamic dispersion (D). The shape of BTC of horizons A and B exhibited tailing, asymmetry, and early appearance of the tracer, but there was no statistical difference between the goodness-of-fit of the CDEeq and CDEneq models. Values of v, D, and dispersivity (λ), indicated that flow in the A and B horizons were dominated by convection and dispersion, whereas the prevalent transport mechanism in C horizons was convection. Values of λ were significantly correlated (r = 0.83; P < 0.05) to clay content mainly because of the correlation between clay and the dispersion coefficients D estimated with either model. Transport properties of soil horizons should be considered when modeling nonreactive solute transport for assessing risks of groundwater contamination.

UR - http://www.scopus.com/inward/record.url?scp=42249086427&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42249086427&partnerID=8YFLogxK

U2 - 10.1097/SS.0b013e31816a1e42

DO - 10.1097/SS.0b013e31816a1e42

M3 - Article

AN - SCOPUS:42249086427

VL - 173

SP - 237

EP - 247

JO - Soil Science

JF - Soil Science

SN - 0038-075X

IS - 4

ER -