A joint Texas-Israel project should result in
automated center pivot and drip irrigation systems that will apply water based
on plant temperature. Click the image for more information about
Texas and Israeli Irrigators Give Plants the Last
By Don Comis
August 10, 2006
Irrigated cotton fields in arid
Israel and Texas may one day be watered automatically based on plant
Evett, an Agricultural Research
Service soil scientist based at the ARS
and Production Research Laboratory in Bushland, Texas, and colleagues are
working with the Israelis on infrared field thermometer sensors to take leaf
temperatures from a short distance. They are designing computer programs that
can automatically translate temperature readings into on/off irrigation
decisions to get the most "crop per drop" of water.
This is the second year of a 3-year project, part of the Binational
Agricultural Research and Development (BARD) program, a joint research program
between Israel and the United States. The Texas work is funded by the state's
Texas-Israel Exchange Fund.
ARS and Israeli scientists are comparing two different methods, both of
which rely on the plant to signal water needs through leaf temperature: the
newer time-temperature threshold, and the older crop water stress index. Both
were developed by ARS.
For cotton, the time-temperature threshold method involves turning on
irrigation when leaf temperature exceeds, for example, 82 degrees F for more
than 4.5 hours. It is based on a discovery by ARS colleagues in Lubbock, Texas,
that each crop has its own preferred temperature range for optimal growth. For
cotton, that range is 73 to 90 degrees F.
The Israelis are using leaf temperatures and the crop water stress index to
predict the water pressure in leaves, a measure of plant water deficit or
Next year the Israeli and ARS researchers will each test both automated
methods, along with a manual system based on soil moisture. Israel uses drip
line irrigation and Texas uses center pivot irrigation.
In addition to the data exchange, the exchange of different irrigation
concepts helps both Israel and the United States get the most out of each
precious drop of water. The ultimate goal is to develop farmer-friendly
wireless irrigation systems.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.