By Brad Haire
University of Georgia
A new grant will help University of Georgia and Clemson
University scientists show farmers a new technology that will
help them conserve water and improve the yields of their
crops.
The scientists will use a three-year, $500,000 Natural Resource
Conservation Service grant to install on farms and conduct field
days for variable-rate irrigation systems.
Five center-pivot irrigation systems in Georgia and one in South
Carolina will be retrofitted with VRI technology each year for
the next three years, said Calvin Perry, a researcher with the
UGA College of Agricultural and Environmental Sciences.
“The goal of this project is to take an innovative product like
VRI to farmers,” said Perry, who is also an engineer with the
UGA department of biological and agricultural engineering, “and
let them test it and see it working and get them interested in
using it.”
Crops have to have water from rain or irrigation to grow
properly. The center pivot is commonly used for irrigation in
Georgia.
A center pivot is a pipe that can be as long as several football
fields. It’s attached to a water pump in the center or at the
edge of a field. Small nozzle sprayers dangle from the pipe,
which can stand 15 feet above the ground. It’s supported by
triangular steel ribs on wheels. The entire system pivots in a
full or half circle in the field.
Farmers don’t have much control over how much water the nozzles
spray as they pass over crops like peanuts, cotton or corn.
Fields, even small ones, can vary widely in topography and soil
types. Some places can be wetter or drier than other places in
the same field.
The concept behind VRI technology 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.
The VRI technology for this project was developed at UGA’s
National Environmentally Sound Production Agriculture Laboratory
in Tifton, Ga. UGA is in the process of getting a patent for the
technology, Perry said.
UGA scientists have tested the water efficiency of VRI systems
on one farmer-owned field in east Georgia and two in south
Georgia. The VRI systems allowed the farmers to place the right
amount of water on their crops for optimal yields and reduce the
water used by 8 percent to 20 percent in each year.
“In most cases,” Perry said, “VRI conserves water.”
There are about 10,000 center pivots in Georgia, said Kerry
Harrison, an irrigation specialist with the UGA Extension
Service. They’re used to water about 75 percent of Georgia’s 1.5
million acres of irrigated cropland.
The grant funds will be used to identify VRI-suitable pivots in
Georgia and South Carolina, Perry said. Web sites and other
educational materials will be created to inform and educate
stakeholders and policymakers in both states on VRI systems’
benefits for communities.
To find out more about VRI, call (229) 386-3377. Or go to the
Web site (www.nespal.org/vri).
