Even after all the rain this spring, soils in Delaware are dry — particularly sandy soil, which cannot hold the moisture, noted representatives of the Delaware Farm Bureau early this week. With temperatures hovering at the 100-degree mark, water evaporates more quickly, too, they noted, so farmers are likely irrigating longer and more often.
The Delaware Department of Agriculture is reminding farmers to make sure their irrigation sys-tems are not spraying water onto state highways and roads. DDA is asking farmers to check the end guns on their pivots and make adjustments, if necessary, to minimize spraying the road.
Wet roadways, they noted, reduce pavement friction, which could create a hazard for motorists — especially for motorcycle riders. A splattered windshield limits visibility, also creating a haz-ard, however briefly.
Richard Wilkins, Delaware Farm Bureau president, said, “As farmers, we try to optimize the quantity of inputs, such as water we apply on our crops. We also should avoid unnecessarily put-ting water on the roadways where it could cause safety concerns for motorists. We will all be much better off by voluntarily avoiding situations that stimulate complaints rather than seeing regulations created that restrict our reasonable use of end guns near roadways.”
Sussex County Farm Bureau President Dale Phillips, who farms in Georgetown, said it is possible to turn irrigation systems off and back on at will, no matter what kind of system a farmer has.
“You used to be able to do it with a mechanical switch,” Phillips said. “Now most systems are controlled electronically, and you can program them, even with your phone, to stop the end gun at a given point and restart after the irrigation system has moved on.”
Paul Cartanza, Kent County farmer, agreed.
“Farmers who have irrigation really need to be cautious, and so do drivers. Water on the road is dangerous for a car or motorcycle. The end gun should be turned off before it gets to the road and back on after it clears the road.”
University of Delaware Irrigation Engineer James Adkins said some older systems didn’t have a mechanism to turn the gun off.
Some systems use a ramp mechanism at the pivot point to control the gun, he explained. Those ramps are not perfect.
“They are usually slightly curved, with the direction of the curve changing with system travel direction. As a system ages, the curvature increases as the joints and alignment cams wear, caus-ing the reduced accuracy of the end gun shutoff based on pivot point angle,” Adkins said.
“Some systems use a digital shaft encoder to control the gun. This method has the same suscep-tibility to wear as the ramp, with the added error of an encoder that may slip slightly on the shaft combined with gear train backlash.
“I recalibrate the shaft encoder on the Warrington (Irrigation Research) Farm system yearly, and it is currently off by 3 to 4 degrees,” he added. “That 4 degrees of error is 50-plus feet on a four-span machine and over 100 feet on an eight-span pivot.”
Adkins continued, “Center pivots are magnets for lightning. Oftentimes, a lightning strike will fry just the shaft encoder, leaving the pivot operating but with no end-gun control. I have had the shaft encoder electronics struck three years in a row, leaving me with a functional irrigation sys-tem without control of the end gun.”
Wind can also cause irrigation water to hit a road.
“End guns throw water from 100 to 150 feet,” Adkins said. “The long range, combined with the 12-foot-high mounting of the gun, makes the water very susceptible to wind drift 100 feet or more off target.”
Adkins added there is no warning if a part fails.
Motorists should be aware that farmers are using irrigation systems at this time of year, even after dark, and should practice caution if roadways are getting wet, he said.