ARLINGTON, Ga. - A top U.S. agricultural official visited southwest Georgia last week to learn how farmers in the drought-prone Flint River Basin have combined a rural wireless network with sophisticated soil monitors and smart irrigation systems to conserve millions of gallons of water.
The visit by Meryln Carlson, a deputy secretary of agriculture, was billed as a Celebration of Water on the eve of Earth Day. He attended a luncheon at the Quail Country Plantation, one of many hunting preserves in the area, before heading to a dusty corn field for a demonstration.
Mr. Carlson saw one of 20 irrigation systems fitted with variable-rate nozzles that spray precise amounts of water only where needed. Conventional systems spray the same volume throughout a field.
"What you've prototyped here is certainly something that will be used by the rest of the nation for precision agriculture," he said, as the 2,200-foot center-pivot irrigation system passed over the 328-acre field.
The system's nozzles turned off when they passed over a weedy low area that didn't need water. They reduced the flow when they passed over a strip covered with grasses that sustain quail.
Graham Ginn, who led the innovative project, said the 20 systems can save 120 million gallons of water in a dry summer by applying 77 percent less water than conventional systems. They used about 17 percent less water than conventional systems during their first summer last year, saving about 128 million gallons, he said.
Farmers received normal rainfall last year, but this summer is expected to be dry.
Water conservation became a critical issue in the Flint River Basin during a 1998-2002 drought when flows in the Flint dropped dangerously low and a few private wells dried up, leaving homeowners without drinking water.
To conserve water, the state ordered a moratorium in 1999 on the drilling of new agricultural wells and paid some farmers to forego irrigation in 2001-02. With the recent lifting of the moratorium, the state has a backlog of 1,100 well-drilling applications.
Mr. Carlson said he was impressed with the conservation potential of the cutting-edge technology being used in southwestern Georgia, where some of the state's most fertile peanut and cotton fields are located.
The variable-rate irrigation systems are controlled by computers and global positioning satellite systems, based on aerial maps showing areas that need the most and least water.
The mapping information is then programmed into the computers.
The wireless network, covering about 100 square miles in rural Calhoun County, allows farmers to monitor soil-moisture conditions in their fields by logging on to the Internet from home or office computers, or from Paris, for that matter.
The soil monitors transmit signals wirelessly that give farmers real-time information, saving fuel that they would normally consume making trips to the field at all hours of the day and night.
"The variable-rate irrigation pilot project has been a great success," said Mr. Carlson, a farmer and rancher from Lodgepole, Neb. "We support this culture of responsibility."
More irrigation systems are planned this year and eventually the wireless network may be used to provide rural residents in the area with high-speed, wireless broadband access, Mr. Ginn said.
With the entire Southeast drier than normal, farmers are once again wondering about the fate of their crops.
Because of the variability of the climate in the region, they have become increasingly dependent on irrigation systems to sustain crops through the hot and often dry summer months.