By Brad Haire
University of Georgia

A technology developed on the Tifton, Ga., University of
Georgia campus that can help farmers improve yields and
conserve water is now being studied in other states.

Crops have to have water from rain or irrigation to grow
properly. The center pivot is commonly used for irrigation in
Georgia.

But farmers don’t have much control over how much water the
irrigation nozzles spray as they pass over crops like peanuts,
cotton or corn. And even small fields can vary widely in
topography and soil types. Some places can be wetter or drier
than other places in the same field.

Variable-rate irrigation takes all of this into consideration,
says Calvin Perry, an agricultural engineer with the UGA
College of Agricultural and Environmental Sciences.

The VRI concept is simple: Apply water when and where crops
need it. Don’t apply it where they don’t. VRI technology uses
computer maps, sensors and software to control where and how
much water the nozzles on a center pivot spray on crops.

Researchers with the UGA National Environmentally Sound
Production Agriculture Laboratory in Tifton started developing
VRI in the late 1990s.

UGA scientists have tested the water efficiency of VRI on farms
in Georgia. The systems allowed the farmers to place the right
amount of water on their crops for the best yields and reduce
the water used by 8 percent to 20 percent in each year.

Using a $500,000 Natural Resource Conservation Service grant,
Perry and other CAES specialists are now sharing the
technology’s potential with researchers and farmers in other
states.

In cooperation with Clemson University, VRI systems are now
studied in South Carolina and being demonstrated to farmers
there.

This spring, in cooperation with the University of Arkansas,
the technology was installed in Poinsett County, Ark., on a
4,000-acre plantation. It’s part of the Judd Hill Foundation,
established in 1985 to foster research and public outreach on
progressive techniques in farming.

“Researchers there are working on their own pivot irrigation
studies and thought VRI would be a good complement to it,”
Perry said. “Agricultural water use is a big issue in Arkansas
just like in Georgia.”

The VRI system received much attention during the plantation’s
annual field day Aug. 31, Perry said.

“This opportunity in Arkansas will allow us to see how the VRI
product does under other climate conditions and other soil
conditions, particularly how it does in the cotton-growing
Arkansas Delta region,” Perry said.