Considering the severe drought suffered by Southeastern farmers during the past two years, it was not surprising that this year’s Sunbelt Ag Expo Field Day was focused to some extent on irrigation.

Variable rate irrigation (VRI) is a technology that was developed at the University of Georgia and is now being sold commercially by Advanced Ag Systems, Inc.

“The idea is that if you farm, you know there are a lot of variables,” says Calvin Perry, superintendent of the Stripling Irrigation Park in Camilla, Ga.

“Typically, you have several soil types and textures. We already know water is a premium commodity, and one day it could become an allocated resource.”

Perry along with a representative from Advanced Ag Systems gave a demonstration of variable rate irrigation during field day on July 7, in Moultrie, Ga.

“We’re trying to be proactive and help growers do a better job of using our water resources,” says Perry.

The VRI system being demonstrated at the Sunbelt Expo site has a control box mounted at the pivot point and a control valve on the sprinklers, he explains.

“We’re able to develop an application map, similar to a chemical or fertilizer application map. But instead of a truck going out and following this map, the pivot point has GPS on it. So as it makes its way around the circle, it knows how much water to apply,” he says.

The Farmscan 7000SL system also controls pivot travel speed and end-gun function for optimal efficiency.

In today’s environment, says Perry, most growers are interested in turning it off in non-crop areas. “We’ve had more interest in growers putting small sensors on their pivots and taking out small sections, such as when the system runs across temporary ponds and other non-crop areas,” he says.

Sprinklers are grouped into banks and these banks are controlled by either an air or a water pilot line that turns off the water. The VRI system also takes into consideration that with several crops under production, harvest timing and watering regimes often are different.

Also at Field Day, Antonio Fleming, tech services manager for the Georgia Soil and Water Conservation Commission, reminded growers that there’s more than one use for their state-mandated irrigation water meters.

“The state passed a law a few years ago requiring that permanent agricultural irrigation sites should be metered,” says Fleming.

“This helps us to keep up with the amount of water our farmers need in Georgia. We have been sued by other states over water rights, and if we ever have to go through our court battle, we have to know the water needs of our farmers.”