The practice of chemigation—the overall term for applying pesticides or fertilizers through center pivots—peaked in the 1980s and early 1990s when farmers treated for corn borer infestations, and then the practice subsided with the introduction of transgenic hybrids with Bt traits for corn borer control.
Richard Ferguson, University of Nebraska soils specialist, believes more farmers ought to consider applying nitrogen through pivots to spoon feed nitrogen, especially since 80% of Nebraska's 8 million irrigated acres watered by sprinklers. "We should be taking more advantage of fertigation. We are in a good position in Nebraska to do so.
"It is an efficient method of supplying part of the nitrogen needed by the crop near the time of maximum nitrogen uptake," Ferguson says. "It's also a stewardship practice by preventing nitrate leaching to the groundwater."
While it varies by hybrid, the most rapid period of uptake is between the eight-leaf stage and tasseling, a time a steady supply is critical for optimum yield.
Bill Kranz, University of Nebraska irrigation engineer who coordinates the chemigation certification training each year, has seen a moderate increase in the number of farmers or other operators the past two years taking the 2- to 3-hour course to become certified chemigation applicators.
The Upper Big Blue NRD, based in York, encourages use of fertigation, says Rod DeBuhr, the district's water department manager. Nebraska's natural resources districts, under the 1987 Nebraska Chemigation Act, are charged with inspecting irrigation systems that are equipped with several mandated safety components when applying pesticides or fertilizer.
Nebraska passed the state Chemigation Act in 1987 to prevent backflow of chemicals or fertilizers from the irrigation system to groundwater in case of a breakdown.
The Nebraska Department of Environmental Quality oversees the program and its requirements. The agency contracts with UNL to conduct certification training for chemigation operators, which can be farmers, one or more of their employees, a crop consultant or an agronomist. Those who become certified can't transfer the certification to someone else on the farm.
After the training course is taken, a test at the end of the session must be passed. Certification lasts for four years.
A certified chemigator submits the paperwork to his or her natural resources district which then issues the permit.
NRDs, under the law, also inspect chemigation setups. If you're newly certified, your system will be inspected before it can be operated. Inspection of permits renewals depends on the NRD, but usually its every three to four years.
Dates and locations for UNL-sponsored certification training sessions this year had not been finalized at this writing. For information on the schedule, contact your local Extension educator or Bill Kranz, UNL Extension irrigation engineer, at 402-584-3857. His email address is email@example.com.
However, the University of Nebraska-Lincoln Extension is set to unveil an Internet-based chemigation training program later in February.
UNL's Kranz says the web-based training program is intended for those needing to recertify, not for those becoming certified for the first time.
"The training program covers all the information presented at the in-person training sessions," he says. "You will be able to access the new training program from anywhere Internet access is available."
The training consists of a series of modules which contain text, video clips and calculators to provide chemigators with the necessary information to employ chemigation in an effective, efficient and environmentally safe manner while safeguarding farm workers involved in chemigation," according to Kranz.
He says that training is self-paced and can be done over several visits to the website.
The online program, like the in-person sessions, requires taking a test after completing the training. However, the tests aren't available in the same program. Instead, those finishing the online training must go to one of 16 Extension office locations in Nebraska to take the test.
Those testing sites for online testing and contact numbers are:
Grand Island, 308-385-5088
North Platte, 308-532-2683
Again, you can contact Kranz at 402-584-3857 or your county Extension educator.
Once the program has been released, producers will be able to go to http://water.unl.edu/web/cropswater/chemigation. Once there, you'll find links to "chemigation course directions," where you can sign in, and then to "proceed to chemigation training."