This summer, a few south Georgia farmers are going decidedly low-tech — a toilet float bobbing in a wash tub tells them when it is time to water their crops.
The UGA EASY Pan Irrigation Scheduler, a moisture indicator, is the result of about 10 years of research by two University of Georgia agricultural engineers.
The wash tub collects water from rain and irrigation and the float moves up and down as the water level changes. A rod connected to the float moves a pointer across a metal backboard with lines.
When the pointer aligns with the red line, it's time to irrigate.
“It's just like the gas gauge in a car,” said Kerry Harrison, one of the developers. Twenty of the unimposing units are already in the fields in Georgia, and its inventors believe it could be used in other Southern states.
While perfecting EASY Pan, the two engineers and some of their colleagues had to consider many factors, such as the water-holding capacity of soils, the evaporation rates for various crops and the water needs of crops such as peanuts and cotton.
The top of the wash tub is covered with screen wire to compensate for differing evaporation rates. The density of the screen can speed up or slow evaporation. For peanuts, they use chicken wire; for cotton, window.
“A farmer might be embarrassed to put it in the field for the first time, but then he will realize, ‘Hey, this is helping me to keep track of the water needs of the crop,’” said co-developer Dan Thomas.
About half of Georgia's cropland — 1.5 million acres — is irrigated and certain high-value crops such as vegetables and tobacco are totally irrigated.
Irrigation is especially important with the current low commodity prices.
If farmers pump too much water, fuel costs can erode profits.
If they don't pump enough, yields drop and that also lowers profits.