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Agricultural engineers Susan O'Shaughnessy and Nolan Clark adjust an infrared thermometer that measures crop canopy temperature as a way of controlling a center pivot irrigation system. Click the image for more information about it.

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Precision Irrigation Built into Sprinkler Booms

By Don Comis
April 15, 2008

A system that turns irrigation water on and off automatically based on leaf temperature is being developed by Agricultural Research Service (ARS) soil scientist Steven Evett and colleagues in Texas.

Evett, a soil scientist at Bushland, Texas, and cooperators are developing time-temperature threshold (TTT) technology that is based in part on a discovery by Evett's colleagues at Lubbock, Texas, that plants grow best at certain narrow temperature ranges that vary by crop species.

Later developments by Evett and his colleagues led to invention of an irrigation control system that uses feedback from the crop, in terms of leaf temperatures, to control irrigation and crop water use efficiency.

Evett's colleague Susan O'Shaughnessy, an agricultural engineer at the ARS Soil and Water Management Research Unit at Bushland, has developed wireless infrared thermometers mounted on center pivot irrigation arms as well as in the field. She is also integrating sensors that can help determine whether to skip watering parts of a field because plants are suffering from disease rather than drought or because no plants have survived in that part of the field.

Ultimately, she and Evett will seek a cooperative research and development agreement with a center pivot manufacturing company that can build the sensors and control system into their equipment.

This research is part of the Ogallala Aquifer Program started in 2004, a partnership between ARS and the Ogallala region's universities. The Ogallala Aquifer underlies eight states from Texas to South Dakota and is one of the world's major aquifers. The goal of the Ogallala Aquifer Program is to protect the towns and their livelihoods, including agricultural industries, by stopping the depletion of the aquifer.

Water availability is key to farming in the Ogallala region. Automated irrigation systems are seen as one major way to move towards sustainable use of the aquifer because they can reduce water use while enhancing profitability due to the reduction in pumping costs.

Read more about the research in the April 2008 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief scientific research agency.