Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/25/2014
Publication Date: N/A
Technical Abstract: A waveguide-on-access-tube (WOAT) sensor system based on time domain reflectometry (TDR) principles was developed to sense soil water content and bulk electrical conductivity in 20-cm (8 inch) deep layers from the soil surface to depths of 3 m (10 ft) (patent No. 13/404,491 pending). A Cooperative Research and Development Agreement (CRADA) was signed with a commercial producer of soil water sensing systems to commercialize the design. Design was based on electromagnetic modeling backed up by construction and laboratory testing of WOAT segments. Two Small Business Innovative Research (SBIR) grants were obtained to first prototype and demonstrate feasibility and then to commercialize the system; and a patent application was filed. Field tests revealed mechanical strength issues that caused redesign to include reinforcing metal. Further field tests pushed the design to a stainless steel tube, which the partner company is presently prototyping for manufacture. In a parallel effort, new TDR calibration and waveform interpretation methods were invented by ARS. Several large users of soil water sensors and the International Atomic Energy Agency (IAEA) have expressed interest. The IAEA expects to utilize the sensor system in a multi-national cooperative research project on salinity in agriculture.