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Treating pests: Chemigation provides options for farmers

by Wyoming Livestock Roundup

“Chemigation is the safe application of pesticides and fertilizers through a water application device, such as a center pivot, so growers can safely apply these products to their land to manage pests or fertilize their crops,” says University of Nebraska-Lincoln Extension Educator Gary Stone.

Stone outlines important considerations growers should take when choosing whether chemigation is the most economical option for their operation.


Each state has their own set of unique requirements for safety equipment to be used during chemigation practices, explains Stone.

According to a bulletin revised in 2013 by the University of Wyoming Extension titled, Chemigation Practices in Wyoming, “Wyoming currently has no laws governing application of chemicals through irrigation water.”

The bulletin continues, “However, groundwater wells used for chemigation may need to be permitted in the near future under the Wyoming Environmental Quality Act.”

Stone notes, “Nebraska requires that the site where the well or pivots are located must have six different safety pieces of equipment before the chemigation application can take place.”

The six required pieces of equipment include a pipeline check valve, a vacuum release valve, a chemical line check valve, an inspection port, a low pressure drain and an interlock, which shuts down the application pump and well pump simultaneously if either malfunction.


According to Stone, applicators must first obtain a chemigation applicators license.

“The applicator has to attend a class, watch videos and then take and pass a test. That certification is good for four years,” he says.

The site of the application must also be inspected to make sure that all safety features are in place and properly functioning.

“These have to be checked every year by the local Natural Resource District (NRD),” continues Stone. “They charge a fee to do inspections, and they issue a permit that the landowner can chemigate through that site.”

If the applicator is applying any restricted-use pesticides through the water, they must also obtain a certified pesticide applicator license.

“To sum it up, they need a certified pesticide applicator license and a chemigation applicators license. Then, the site has to be permitted by the NRD before any application can take place,” comments Stone.


“What growers really need to determine is if chemigation is their best option,” says Stone, noting that producers should consider if aerial or ground application could be done more quickly, easily and at less cost.

Important factors to consider when choosing which application option to use include stage of crop growth and pest infestation. The pesticide label must state that it can be used in chemigation.

“If producers have a pest that’s after their crop, it might cheaper to go with another option, but if they have the time and are set up to chemigate, it may be a viable option,” Stone continues. “It’s a matter of economics and timing of the application.”

If growers have time to apply the product and are applying a large amount of product, chemigation may be the most economical option.

  “If they have plenty of time to put a fertilizer on, like three or four days, which isn’t as big of a rush, and they’ve actually got a lot more product going on, it might be easier to run it through a pivot than, say. a ground rig,” he says.


According to Stone, most center pivots installed in the Nebraska Panhandle typically include the required safety features for chemigation in the package.

“Pivot companies include chemigation safety features as a standard package because, if a grower wants to put something in, it’s easier to put all of these features in the first time than to come back later to put all of the safety equipment on,” he explains.

Growers could acquire the injection pump from an ag chemical dealer either included in the chemical cost or at a small additional fee per acre of use.

“Dealers may either provide the pump as a service to the grower because they’re purchasing product through the company, or they may charge a minimal cost,” says Stone. “There is also the option to utilize a tank for chemicals.”

Another equipment option would include a water meter for wells to measure flow rate or the output of the well.

“In the Panhandle, nearly all of the agricultural wells have to have a water meter on them,” concludes Stone. “There’s usually a cost share that the NRD has with our growers to put in those flow meters.”

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at

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