Very few Georgia farmers use advanced irrigation scheduling techniques to manage irrigation on their farms because they often find it overwhelming or too costly to implement.

Wesley Porter, right, Extension precision agriculture and irrigation specialist with the University of Georgia, discusses the benefits of advanced irrigation scheduling treatments in peanuts, with Clemson University Extension economist Nathan Smith during the annual meeting of the American Peanut Research and Education Society.

“The people that use advanced irrigation techniques are usually consultants in Georgia. There is a lot of data and you have to interpret that data and make decisions from that data. Sometimes producers find it is a little overwhelming and easier to pay somebody else to work with it,” says Wesley Porter, Extension precision agriculture and irrigation specialist with the University of Georgia in Tifton.

Most farmers still use visible stress to plants to determine their irrigation schedule, Porter said. But in a paper presented to the annual meeting of the American Peanut Research and Education Society in Clearwater, Fla., Porter emphasized that irrigation scheduling treatments are a good way to manage irrigation on the farm.

Porter discussed research at the University of Georgia where five irrigation scheduling treatments along with a rain fed treatment were tested in 2014 and seven irrigation scheduling treatments along with a rain fed treatment were tested in 2015 at the Stripling Irrigation Research Park near Camilla, Ga. The research aims to determine the best option for producers in the Southeast.

“The data show that the utilization of any type of irrigation scheduling method helps potentially increase yield and reduce the amount of irrigation applied to the crop in either year tested,” Porter said.

Sensor-based methods produce most consistent highest yields

The seven methods tested were a soil moisture system developed by the University of Georgia which consisted of three Watermark sensors, a SmartCrop  canopy temperature sensor utilizing a Crop Water Stress Index, the UGA EasyPan, the UGA Peanut Checkbook Method and the University of Florida’s PeanutFarm system.

In the research, four cultivars commonly planted in Georgia were planted in two-row plots within each irrigation zone. The four cultivars were GA-06G, GA-12Y, TUFRunner 511, and TUFRunner 727.

“Variety differences were observed with the GA-06G generally being the highest yielding variety in each case,” Porter said.

Porter noted that 2014 and 2015 were two different dynamic years. “During the 2014 production season, 12.33 inches of rainfall were received while 22.65 inches of rainfall was received during the 2015 production season,” he said.

Research shows that 23 inches of water is optimal for peanuts from planting to harvest, Porter explained. Approximately 18 inches of this water is needed from weeks 10 to 17 of the 20 week peanut growing season.

The 12.33 inches of rain received in 2014 is pretty typical for a production year in Georgia. “The problem with a year like 2014 is a lot of the rain came early or very late, during the hottest time of the year. We didn’t get the rain we needed for these crops,” Porter said. “The weighted sensor average called for about 9.5 inches of additional irrigation for about 22 inches of water that year.”

Rainfall proved much better in 2015 with water generally evenly distributed through rainfall events throughout the year, Porter said.

“Sensor-based methods produced the most consistent highest yields in both years. Timing is more critical than the amounts. Web based scheduling tools seem to be doing very well,” Porter said.