A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors

Affordable, commercial dielectric sensors of the frequency domain reflectometry (FDR) and capacitance–conductance (CC) types estimate the dielectric permittivity (εb) and electrical conductivity (σb) of bulk soil. In this work, an equation was obtained to estimate the pore-water electrical conductiv...

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Main Authors: Visconti, Fernando, Martínez, Delfina, Molina, María J., Ingelmo, Florencio, De-Paz, José M.
Format: Artículo
Language:Inglés
Published: 2017
Online Access:http://hdl.handle.net/20.500.11939/4742
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author Visconti, Fernando
Martínez, Delfina
Molina, María J.
Ingelmo, Florencio
De-Paz, José M.
author_browse De-Paz, José M.
Ingelmo, Florencio
Martínez, Delfina
Molina, María J.
Visconti, Fernando
author_facet Visconti, Fernando
Martínez, Delfina
Molina, María J.
Ingelmo, Florencio
De-Paz, José M.
author_sort Visconti, Fernando
collection ReDivia
description Affordable, commercial dielectric sensors of the frequency domain reflectometry (FDR) and capacitance–conductance (CC) types estimate the dielectric permittivity (εb) and electrical conductivity (σb) of bulk soil. In this work, an equation was obtained to estimate the pore-water electrical conductivity (σp), which is closely related to the soil salinity in contact with plant roots, from εb and σb data, by combining the simplified dielectric mixing (SDM) model that relates εb to the soil volumetric water content (θ), with the Rhoades equation that relates θ and σb to σp. This equation was calibrated with measurements of εb and σb obtained with the Delta-T WET (FDR) and the Decagon 5TE (CC) sensors, in 20 pots filled with a clay loam soil and arranged as combinations of four levels of soil moisture with five levels of soil salinity. The calibrations were performed against reference θ and σp values. The σp was calculated with the chemical equilibrium model SALSOLCHEMEC and used as a more reliable reference than the electrical conductivity of the soil wetting water. For both sensors, the SDM model on the one hand, and the Rhoades equation on the other, provided the most accurate estimations using the least number of parameters regarding their respective alternatives, i.e. the third-order polynomial and the Hilhorst equation. The combined equation for estimation of σp subsequently provided root mean square deviations of 3.1 (WET) and 4.1 (5TE) dS m–1, which decreased to 1.5 and 2.6 dS m–1 for θ >0.22 m3 m–3, and σb <3 (WET) and 3.7 (5TE) dS m–1. A new combined equation has been proposed for reliable estimations of σp with these sensors in clayey soils for θ >0.22 m3 m–3 and σb <3.7 dS m–1.
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institution Instituto Valenciano de Investigaciones Agrarias (IVIA)
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spelling ReDivia47422025-04-25T14:44:18Z A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors Visconti, Fernando Martínez, Delfina Molina, María J. Ingelmo, Florencio De-Paz, José M. Affordable, commercial dielectric sensors of the frequency domain reflectometry (FDR) and capacitance–conductance (CC) types estimate the dielectric permittivity (εb) and electrical conductivity (σb) of bulk soil. In this work, an equation was obtained to estimate the pore-water electrical conductivity (σp), which is closely related to the soil salinity in contact with plant roots, from εb and σb data, by combining the simplified dielectric mixing (SDM) model that relates εb to the soil volumetric water content (θ), with the Rhoades equation that relates θ and σb to σp. This equation was calibrated with measurements of εb and σb obtained with the Delta-T WET (FDR) and the Decagon 5TE (CC) sensors, in 20 pots filled with a clay loam soil and arranged as combinations of four levels of soil moisture with five levels of soil salinity. The calibrations were performed against reference θ and σp values. The σp was calculated with the chemical equilibrium model SALSOLCHEMEC and used as a more reliable reference than the electrical conductivity of the soil wetting water. For both sensors, the SDM model on the one hand, and the Rhoades equation on the other, provided the most accurate estimations using the least number of parameters regarding their respective alternatives, i.e. the third-order polynomial and the Hilhorst equation. The combined equation for estimation of σp subsequently provided root mean square deviations of 3.1 (WET) and 4.1 (5TE) dS m–1, which decreased to 1.5 and 2.6 dS m–1 for θ >0.22 m3 m–3, and σb <3 (WET) and 3.7 (5TE) dS m–1. A new combined equation has been proposed for reliable estimations of σp with these sensors in clayey soils for θ >0.22 m3 m–3 and σb <3.7 dS m–1. 2017-06-01T10:10:53Z 2017-06-01T10:10:53Z 2014 2014 article Visconti, F., Martinez, Delfina, J. Molina, M., Ingelmo, Florencio, Paz, J. Miguel de (2014). A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors. Soil Research, 52(5), 419-430. 1838-675X http://hdl.handle.net/20.500.11939/4742 10.1071/SR13331 en openAccess Impreso
spellingShingle Visconti, Fernando
Martínez, Delfina
Molina, María J.
Ingelmo, Florencio
De-Paz, José M.
A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title_full A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title_fullStr A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title_full_unstemmed A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title_short A combined equation to estimate the soil pore-water electrical conductivity: calibration with the WET and 5TE sensors
title_sort combined equation to estimate the soil pore water electrical conductivity calibration with the wet and 5te sensors
url http://hdl.handle.net/20.500.11939/4742
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