Soil Matric Potential Determined Using Coiled TDR and a Porous Ceramic Cup. (5520)
Authors:
D.C. Renaud* - Univ. of Saskatchewan B.C. Si - Univ. of Saskatchewan
Abstract:
Soil matric potential is an important variable for hydrological processes in the vadoze zone. Heat dissipation sensors are commonly used to measure matric potential in semi-arid regions. However, sensitivity of this technology may be of concern at low water contents. Time Domain Reflectometry (TDR) provides an accurate and non-destructive means to automatically measure water content,
including typical low moisture levels in semi-arid zones. Therefore, the objective of this study was to determine if combining coiled TDR and a porous ceramic cup would enable the simultaneous measurement of water content in a ceramic cup, thus soil water potential over a greater range of matric suctions than typically associated with heat dissipation sensors. The novel probe consists of a coiled TDR rod inserted into a porous ceramic cup which is then embedded into soil. The ceramic cup
equilibrates with the surrounding soil water content and TDR then measures the water content of the cup. From the water retention properties of the ceramic cup, soil matric potential can be inferred. The probe was tested both gravimetrically and through calibration with a heat dissipation sensor. Preliminary results suggest the new probe is able to accurately characterize soil matric potential at the same level as heat dissipation technology.
Speaker Information: Danielle Renaud, Univ. of Saskatchewan, Department of Soil Sciences University of Saskatchewan 51 Campus Drive, Saskatoon, SK S7N 5A8;
Phone: (306)966-6860; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 7:50 AM-12:05 PM Presentation Start: 10:35 AM
Keywords: soil matric potential; coiled TDR; in-situ; porous ceramic cup