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Titel |
Polymer tensiometers with ceramic cones: direct observations of matric pressures in drying soils |
VerfasserIn |
M. J. Ploeg, H. P. A. Gooren, G. Bakker, C. W. Hoogendam, C. Huiskes, L. K. Koopal, H. Kruidhof, G. H. Rooij |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 14, no. 10 ; Nr. 14, no. 10 (2010-10-04), S.1787-1799 |
Datensatznummer |
250012435
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Publikation (Nr.) |
copernicus.org/hess-14-1787-2010.pdf |
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Zusammenfassung |
Measuring soil water potentials is crucial to characterize vadose zone
processes. Conventional tensiometers only measure until approximately
−0.09 MPa, and indirect methods may suffer from the
non-uniqueness in the relationship between matric potential and measured
properties. Recently developed polymer tensiometers (POTs) are able to
directly measure soil matric potentials until the theoretical wilting point
(−1.6 MPa). By minimizing the volume of polymer solution inside
the POT while maximizing the ceramic area in contact with that polymer
solution, response times drop to acceptable ranges for laboratory and field
conditions. Contact with the soil is drastically improved with the use of
cone-shaped solid ceramics instead of flat ceramics. The comparison between
measured potentials by polymer tensiometers and indirectly obtained
potentials with time domain reflectometry highlights the risk of using the
latter method at low water contents. By combining POT and time domain
reflectometry readings in situ moisture retention curves can be measured
over the range permitted by the measurement range of both POT and time
domain reflectometry. |
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