Soil Water Sensors for Agriculture - Theory and Issues
Webinar Details
When:
Jan 14, 2016 11:30 am US/Eastern
Length: 00:58 (hh:mm)
Advance Registration NOT required.
View now on-demand.
Presenter(s):
- Steven R. Evett, Senior Research Soil Scientist, Lead Scientist, Soil and Water Management Research Unit Conservation & Production Research Laboratory, USDA-ARS, Bushland, TX
Virtual Event Format:
Group Viewing Available:
Participants will learn about the types of soil water sensors available for on farm use and their advantages and limitations for irrigation water management.
Note: an audio distortion is corrected at 11 minutes into this webinar.
Soil water sensors have been used for irrigation and water management in agriculture for many years, but with limited success in many cases. Nonetheless, the use of soil water sensors is increasing as water scarcity increases and, conversely, as problems associated with over irrigation increase. Common problems with soil water sensing include sensor failure, problems with wiring, lack of or failure of data telemetry, inaccurate data, lack of timely data, excessive labor requirements and interference from dynamic soil temperature and bulk electrical conductivity changes. There are many sensors available, but only four main technologies: neutron thermalization, resistance blocks, capacitance sensing (frequency domain sensing), and travel time sensing (time domain reflectometry and time domain transmission modes). Understanding the theory of these offers insight into what a user can expect from each technology in terms of accuracy, stability and representativeness of the readings. The presentation will cover the types of sensors available, the operational theory of each sensor type, and explanations, with examples, of how the physical theory of operation dictates the limits of sensor calibration and performance, and of sensor representativeness in given soils.
This webinar is presented by the USDA NRCS West National Technology Support Center.
View the February 11, 2016, companion webinar: Soil Water Sensors for Agriculture - Applications and Usefulness.
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