Unreconciled effects of salinity on draining and wetting functions in unsaturated soils

Abstract In a sequence of one‐step outflow–inflow experiments, this study examines the effects of salinity on soil hydraulic properties with the goal of developing a better understanding of how to predict salinity's impacts on soils. The results of this study are compared with estimates obtaine...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	David P. Huber, Greg L. Butters, Luis A. Garcia
Formato:	article
Lenguaje:	EN
Publicado:	Wiley 2021
Materias:	Environmental sciences GE1-350 Geology QE1-996.5
Acceso en línea:	https://doaj.org/article/ac4abd1b4a464c6f98e42146063f1991
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:ac4abd1b4a464c6f98e42146063f1991
record_format	dspace
spelling	oai:doaj.org-article:ac4abd1b4a464c6f98e42146063f19912021-11-25T13:30:33ZUnreconciled effects of salinity on draining and wetting functions in unsaturated soils1539-166310.1002/vzj2.20169https://doaj.org/article/ac4abd1b4a464c6f98e42146063f19912021-11-01T00:00:00Zhttps://doi.org/10.1002/vzj2.20169https://doaj.org/toc/1539-1663Abstract In a sequence of one‐step outflow–inflow experiments, this study examines the effects of salinity on soil hydraulic properties with the goal of developing a better understanding of how to predict salinity's impacts on soils. The results of this study are compared with estimates obtained using the Hydrus‐1D model for soil water and solute transport. The model assumes a decline in hydraulic conductivity (K), caused by solution chemistry, is constant over the entire hydraulic conductivity function [K(θ)] and equal to a constant reduction factor established at saturation. In contrast with the model assumptions, the results of this study show an increase in the solution chemistry's effect on K with decreasing soil moisture (θ). These findings demonstrate that current models that exclude solution chemistry, or models that assume a constant K reduction for the entire K(θ) function, may be overestimating drainage, recharge, or bare soil evaporation. This research used undisturbed soil cores and simulated irrigation water with decreasing electrical conductivity (EC) from 20 to 0.25 dS m–1 and sodium adsorption ratio (SAR) held constant. Changes in K(θ) were observed only after dropping below an EC of 1.5 dS m–1, which is consistent with past studies. At reduced soil water contents, however, K(θ) decreased by up to five orders of magnitude relative to native soils. A second experiment was conducted that increased the SAR from 4 to ≥20, held EC constant at 0.65 dS m–1, and displayed only moderate reductions in K(θ), although K was reduced proportionally more at reduced soil water contents. Therefore, based on the observed results, an integrated K(EC,θ) and K(SAR,θ) model is needed to better predict salinity effects on soil hydraulic properties and is increasingly important as freshwater resources decline.David P. HuberGreg L. ButtersLuis A. GarciaWileyarticleEnvironmental sciencesGE1-350GeologyQE1-996.5ENVadose Zone Journal, Vol 20, Iss 6, Pp n/a-n/a (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Environmental sciences GE1-350 Geology QE1-996.5
spellingShingle	Environmental sciences GE1-350 Geology QE1-996.5 David P. Huber Greg L. Butters Luis A. Garcia Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
description	Abstract In a sequence of one‐step outflow–inflow experiments, this study examines the effects of salinity on soil hydraulic properties with the goal of developing a better understanding of how to predict salinity's impacts on soils. The results of this study are compared with estimates obtained using the Hydrus‐1D model for soil water and solute transport. The model assumes a decline in hydraulic conductivity (K), caused by solution chemistry, is constant over the entire hydraulic conductivity function [K(θ)] and equal to a constant reduction factor established at saturation. In contrast with the model assumptions, the results of this study show an increase in the solution chemistry's effect on K with decreasing soil moisture (θ). These findings demonstrate that current models that exclude solution chemistry, or models that assume a constant K reduction for the entire K(θ) function, may be overestimating drainage, recharge, or bare soil evaporation. This research used undisturbed soil cores and simulated irrigation water with decreasing electrical conductivity (EC) from 20 to 0.25 dS m–1 and sodium adsorption ratio (SAR) held constant. Changes in K(θ) were observed only after dropping below an EC of 1.5 dS m–1, which is consistent with past studies. At reduced soil water contents, however, K(θ) decreased by up to five orders of magnitude relative to native soils. A second experiment was conducted that increased the SAR from 4 to ≥20, held EC constant at 0.65 dS m–1, and displayed only moderate reductions in K(θ), although K was reduced proportionally more at reduced soil water contents. Therefore, based on the observed results, an integrated K(EC,θ) and K(SAR,θ) model is needed to better predict salinity effects on soil hydraulic properties and is increasingly important as freshwater resources decline.
format	article
author	David P. Huber Greg L. Butters Luis A. Garcia
author_facet	David P. Huber Greg L. Butters Luis A. Garcia
author_sort	David P. Huber
title	Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
title_short	Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
title_full	Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
title_fullStr	Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
title_full_unstemmed	Unreconciled effects of salinity on draining and wetting functions in unsaturated soils
title_sort	unreconciled effects of salinity on draining and wetting functions in unsaturated soils
publisher	Wiley
publishDate	2021
url	https://doaj.org/article/ac4abd1b4a464c6f98e42146063f1991
work_keys_str_mv	AT davidphuber unreconciledeffectsofsalinityondrainingandwettingfunctionsinunsaturatedsoils AT greglbutters unreconciledeffectsofsalinityondrainingandwettingfunctionsinunsaturatedsoils AT luisagarcia unreconciledeffectsofsalinityondrainingandwettingfunctionsinunsaturatedsoils
_version_	1718413455725166592

Unreconciled effects of salinity on draining and wetting functions in unsaturated soils

Ejemplares similares