Is wind ever a factor for agriculture? Of course it is, and it is a major factor in efficiency of center-pivot sprinkler irrigation.
While there are many factors that go into deciding which type of sprinkler package is best for your situation, wind and climate considerations are among those at the top of the list. And that impact becomes even greater in more arid climates.
“Wind is really a climatic effect that we are paying the most attention to,” says Josh Mosier, general manager and technical sales director for Komet Irrigation, based in Fremont, Neb. “If water is not hitting the target area, it is ineffective. Water is lost that the plant could use.”
How much water is lost to wind drift and evaporation varies, Mosier says. “In a humid climate, losses could be less than 1%, but in a windy area and arid climate, losses of 45% of applied water due to wind drift and evaporation are not uncommon.”
Water loss come down to physics.
“Fine droplets will evaporate and move easier in the wind, because they don’t have weight to them,” Mosier explains. “Typically, we see heavy droplets in the outside of the sprinkler pattern, and finer droplets inside the wetted pattern.”
The idea in windy regions is to find a sprinkler package that offers the most consistent droplet size over the entire wetted area, he adds.
“You reduce the wind potential with getting rid of the finer droplets, and you want droplet distribution that covers as much ground as possible in as even of a pattern as possible,” Mosier notes. “There is no getting around it. The fine droplets displace the furthest in the wind and carry on wind very easily.”
The best way to evaluate your current sprinkler package under wind is to observe your sprinkler pattern during windy conditions on bare soil. What does it look like? What is your droplet size, and is it inconsistent? Do the droplets have the weight to stay closer to the target area? Is it hard to even see the pattern?
Another factor is droplet collision with water streams coming from the sprinklers.
“Wind drift happens due to reduced spacing and stream collision,” Mosier says. “You can vary up and down so streams do not hit themselves. You can use over-the-truss drops to help spread them out and reduce the impact of collision with streams coming off the sprinkler.”
To reduce the impact of wind, consistent droplet size is optimal, avoiding high pressure and keeping the trajectory of the droplets lower.
Learn more about droplet size, sprinkler packages and the impact of wind at kometirrigation.com.