Short, Multineedle Frequency Domain Reflectometry Sensor Suitable for Measuring Soil Water Content

dc.contributor.author Xu, Jinghui
dc.contributor.author Ma, Xiaoyi
dc.contributor.author Horton, Robert
dc.contributor.author Logsdon, Sally
dc.contributor.author Horton, Robert
dc.contributor.department Agronomy
dc.date 2018-01-25T07:52:13.000
dc.date.accessioned 2020-06-29T23:04:50Z
dc.date.available 2020-06-29T23:04:50Z
dc.date.issued 2012-01-01
dc.description.abstract <p>Time domain reflectometry (TDR) is a well-established electromagnetic technique used to measure soil water content. Time domain reflectometry sensors have been combined with heat pulse sensors to produce thermo-TDR sensors. Thermo-TDR sensors are restricted to having relatively short needles to accurately measure soil thermal properties. Short needle lengths, however, can limit the accuracy of the TDR measurement of soil water content. Frequency domain reflectometry (FDR) sensors are an alternative to TDR sensors that can provide an inexpensive measurement of soil water content. The objective of this study was to determine whether short FDR sensors can accurately measure soil water content. We designed and constructed a short FDR sensor. For four soil types across a range of water contents, temperatures, and salt contents, we measured soil dielectric spectra with the short FDR sensor. A vector network analyzer was used to obtain soil dielectric spectra in the 1-MHz to 3-GHz frequency range. The ideal frequency of a short FDR sensor is the frequency at which the permittivity is not altered by changing temperature or salt content. The 47- to 200-MHz range was an ideal frequency range for measuring soil water content, and 70 MHz was the frequency least influenced by temperature and salt content. The short FDR sensor provided quick, continuous, stable, and cheap measurements of soil water content. Because of the promising performance of the short thermo-FDR sensor in laboratory studies, sensors should be evaluated in future field studies.</p>
dc.description.comments <p>This article is published as Xu, Jinghui, Xiaoyi Ma, Sally D. Logsdon, and Robert Horton. "Short, multineedle frequency domain reflectometry sensor suitable for measuring soil water content." Soil Science Society of America Journal 76, no. 6 (2012): 1929-1937. doi: <a href="http://dx.doi.org/10.2136" target="_blank">10.2136/sssaj2011.0361</a>. Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/agron_pubs/393/
dc.identifier.articleid 1440
dc.identifier.contextkey 11409005
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath agron_pubs/393
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/4746
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/agron_pubs/393/2012_Horton_ShortMultineedle.pdf|||Fri Jan 14 23:55:49 UTC 2022
dc.source.uri 10.2136/sssaj2011.0361
dc.subject.disciplines Agriculture
dc.subject.disciplines Hydrology
dc.subject.disciplines Soil Science
dc.title Short, Multineedle Frequency Domain Reflectometry Sensor Suitable for Measuring Soil Water Content
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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