Sweltering heat and limited rainfall have taken a toll on Leon Knirk’s 1,000-acre corn crop for each of the past four years. In response, the Quincy, Mich., farmer is in the process of putting two center pivots on 200 acres this year.
The pivots will cover Knirk’s lightest soils, those on the farm with the least amount of water-holding capacity.
"We hope by removing the weather variable that we’ll be able to achieve higher and more consistent yields across those fields," he says.
In addition, Knirk expects to see a boost in his corn yield average, which currently hovers at 150 bu. per acre.
Higher prices for corn along with what Knirk says are changing weather patterns, drove his decision to purchase the center pivots.
Other farmers in Great Lakes states are evaluating the payoffs from irrigation for similar reasons, notes Lyndon Kelley, Extension irrigation educator for Indiana and Michigan.
On average, he says corn crops in upper Midwest states require between 6" and 10" of moisture per season to develop into a financially viable crop. While some areas routinely receive the needed moisture, others do not.
Points to ponder. Despite the uptick in farmers’ interest in irrigation, Kelley cautions that there are limiting factors they need to pencil out and consider before jumping on the irrigation bandwagon.
An adequate water supply is at the top of the list of requirements. Kelley says research shows that farmers need a water supply that can provide the crop between 5 gal. and 7 gal. of water per minute per acre.
"The closer your water supply is to 7 gal. per minute the better," he says. "Some grower contracts aren’t viable if you don’t have the minimum requirement."
If farmers are uncertain about the water availability on their farm, Kelley encourages them to hire a licensed well digger or hydrogeologist to investigate.
Water availability was the biggest issue Knirk faced.
"Finding water was a bit more difficult than I had anticipated," he says. "We had five test wells and only one ended up being good. The other four were insufficient, so we had to change course. Now we plan to use ponds, and only one system will run off the well."
A farm’s proximity to water also impacts pumping costs.
"If you can draw the water out of the center of your ground, it’s cheaper than if I have to draw it from the corners because of the energy used," Kelley explains.
Along with water availability, farmers need to evaluate the setup costs, labor costs, interest, depreciation, repairs, taxes and insurance.
In Kelley’s experience, farmers incur annual irrigation expenses as low as $90 per acre to as high as $300 per acre. The size and scale of the system installed contribute to the large cost variation, he says.
Knirk says he planned conservatively for the pivots to pay for themselves in the next five years.
"It could happen faster, maybe in three years, but I didn’t want to push it too hard too fast," he says.
Along with the financial considerations, farmers need to consult state laws before they purchase any type of irrigation system as there might be legal constraints.
While most farmers would agree that growing more corn per acre is a benefit, Kelley points out there are some potential pitfalls.
"You have to have adequate harvesting equipment and enough labor to handle more bushels per acre," he says. "With more bushels you may also have more drying costs."
Some irrigation systems require more manpower. Research cited by Larry C. Brown, Extension agricultural engineer, Ohio State University, indicates that one human-hour per acre per day is required for hand-moved irrigation systems. Mechanically moved systems, however, require only 10% to 50% as much labor.