Field determination of soil hydraulic and chemical transport properties

dc.contributor.author Al-Jabri, Salem
dc.contributor.author Horton, Robert
dc.contributor.author Horton, Robert
dc.contributor.author Jaynes, Dan
dc.contributor.author Gaur, Anju
dc.contributor.department Agronomy
dc.date 2018-02-12T22:48:05.000
dc.date.accessioned 2020-06-29T23:05:12Z
dc.date.available 2020-06-29T23:05:12Z
dc.date.issued 2002-06-01
dc.description.abstract <p>Hydraulic and chemical transport properties are the major inputs in predictive models that simulate the movement of water and chemicals through the vadose zone. However, there is a lack of field measurements of such properties to verify models describing water and chemical movement through the soil. One of the objectives of this study was to use a point source method to determine simultaneously the hydraulic and chemical transport properties at multiple field locations. A second objective was to determine the spatial distribution of such properties across a field. A total of 50 field locations within a 7 × 15-m area were rapidly and simultaneously evaluated for such properties. The hydraulic properties were the saturated hydraulic conductivity (<em>Ks</em>) and the macroscopic capillary length (λ<em>c</em>). The chemical transport properties were the immobile water content, expressed as a fraction of water content (θ<em>im</em>/θ) and the mass exchange coefficient (α). The hydraulic properties were determined by applying three discharge rates from irrigation dripper lines and measuring the resultant steady-state flux densities at the soil surface beneath each emitter. The chemical transport properties were determined by applying a sequence of three conservative tracers at a steady-state infiltration rate and measuring their resident concentration in the soil. The <em>Ks</em> values ranged from 7.5 to 79.0 cm h−1, with a median of 27.4 cm h−1 (± 16.8). The λ<em>c</em> values ranged from 0.03 to 13.1 cm, with a median of 2.6 cm (± 3.6). The θ<em>im</em>/θ values ranged from 0.36 to 0.88, with a median of 0.57 (± 0.098). The α values ranged from 0.002 to 0.12 h−1, with a median of 0.034 h−1 (± 0.027). The values of the hydraulic and chemical transport parameters were found to be comparable with values reported by studies conducted on nearby field locations on similar soil. Based on semivariogram analysis, the measured properties were not spatially correlated. Because the method required only 2 days to collect data it should prove useful for future studies that require extensive field measurements of hydraulic and chemical transport properties.</p>
dc.description.comments <p>This article is published as Al-Jabri, Salem A., Robert Horton, Dan B. Jaynes, and Anju Gaur. "Field determination of soil hydraulic and chemical transport properties." <em>Soil science</em> 167, no. 6 (2002): 353-368.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/agron_pubs/434/
dc.identifier.articleid 1483
dc.identifier.contextkey 11529762
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath agron_pubs/434
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/4792
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/agron_pubs/434/2002_Horton_FieldDetermination002.PDF|||Sat Jan 15 00:16:04 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Hydrology
dc.subject.disciplines Soil Science
dc.subject.keywords Solute transport properties
dc.subject.keywords hydraulic conductivity
dc.subject.keywords spatial variability
dc.title Field determination of soil hydraulic and chemical transport properties
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication d3fb0917-6868-417e-9695-a010896cfafa
relation.isOrgUnitOfPublication fdd5c06c-bdbe-469c-a38e-51e664fece7a
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