HR: 0800h
AN: H11A-0149    [Abstracts]
TI: Advances in Determining Soil Matric Potential Using an Engineered Porous Ceramic and Dielectric Permittivity
AU: * Cobos, D R
EM: doug@decagon.com
AF: Decagon Devices, 2365 NE Hopkins Ct., Pullman, WA 99163, United States
AU: Campbell, C S
EM: colin@decagon.com
AF: Decagon Devices, 2365 NE Hopkins Ct., Pullman, WA 99163, United States
AU: Campbell, G S
EM: gaylon@decagon.com
AF: Decagon Devices, 2365 NE Hopkins Ct., Pullman, WA 99163, United States
AB: Soil water potential is a key parameter for determining water availability for plant growth, water flow, and soil stability. Although an in situ measurement of matric potential has been the focus of considerable research over the years, existing solutions still have many draw backs such as high maintenance, limited longevity, individual calibration requirements, high cost, and small measurement range. The objective of this research was to develop a sensor that could be used in the field to accurately measure soil matric potential without the limitations noted above. The sensor, which consisted of a dielectric sensor sandwiched between porous ceramic, was tested over a range soil types, electrical conductivties, and temperatures to calibrate and characterize its output. Data show consistent calibration curves between sensor output and actual soil matric potential over a variety of soil textures and electrical conductivities. Although temperature showed an effect on sensor output, it was low compared to overall sensor output. Likewise, salt effects were not visible in saturated matrices up to 10 dS/m. Data suggest the sensor will be an effective and robust tool to determine in situ matric potential.
DE: 1848 Monitoring networks
DE: 1866 Soil moisture
DE: 1875 Vadose zone
DE: 1880 Water management (6334)
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: 2007 Fall Meeting