| Volumes and Issues Contents of Issue 3 |
www.hydrol-earth-syst-sci-discuss.net/6/4349/2009/
doi:10.5194/hessd-6-4349-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Polymer tensiometers with ceramic cones: performance in drying soils and comparison with water-filled tensiometers and time domain reflectometry
1Dep. Environmental Sciences, Soil Physics, Ecohydrology and Groundwater Management Group, Wageningen University, The Netherlands
2ALTERRA, Wageningen, The Netherlands
3Laboratory for Physical Chemistry and Colloid Science, Wageningen University, The Netherlands
4Faculty of Science and Technology, Twente University, The Netherlands
Abstract. Measuring soil water potentials is crucial to characterize vadose zone processes. Water-filled tensiometers only measure until approximately −0.085 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 a 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 time domain reflectometry.
Discussion Paper (PDF, 3035 KB) Interactive Discussion (Closed, 4 Comments) Manuscript under review for HESS
Citation: van der Ploeg, M. J., Gooren, H. P. A., Bakker, G., Hoogendam, C. W., Huiskes, C., Koopal, L. K., Kruidhof, H., and de Rooij, G. H.: Polymer tensiometers with ceramic cones: performance in drying soils and comparison with water-filled tensiometers and time domain reflectometry, Hydrol. Earth Syst. Sci. Discuss., 6, 4349-4377, doi:10.5194/hessd-6-4349-2009, 2009. Bibtex EndNote Reference Manager XML
