Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/4/2015
Publication Date: N/A
Technical Abstract: Effective irrigation management is key to obtaining the most crop production per unit of water applied and increasing production in the face of competing demands on water resources. Management methods have included calculating crop water needs based on weather station measurements, calculating soil water deficits in the crop root zone based on soil water sensing, and estimating crop water stress from measurements of plant characteristics such as canopy temperature. Scientists at the USDA-ARS Soil and Water Management Research Unit, Bushland, Texas, combined all three approaches in a patented Irrigation Scheduling and Supervisory Control and Data Acquisition (ISSCADA) system. A new, accurate Waveguide-On-Access-Tube (WOAT) soil water sensor based on time domain reflectometry (TDR) was also patented by the scientists and was tested in the field. Results from the 2015 field tests show that the sensor is reliable, accurate and reports soil bulk electrical conductivity (BEC) as well as soil water content and temperature. Since the BEC reading indicates the degree of soil salinization, the sensor can be used to manage irrigation using brackish waters and in salt affected soils, broadening the impact of this new sensor system. Examples of integraton of the soil water sensor with the ISSCADA system show how irrigation management can be improved thorugh sensor feedback control.