Using subsurface drip irrigation, Nebraska farmer Don Anthony has maintained big corn and soybean yields while improving his watering efficiency by 35% or more. Like many western Corn Belt and southern High Plains growers with limited annual rainfall, Anthony has counted on irrigation as a staple for his corn, soybeans and other crops.
But with many areas seeing dwindling aquifers and/or government restrictions, subsurface drip irrigation (SDI) is replacing center pivots and furrow irrigation on some acres.
More than 300,000 acres are in drip irrigation across the Great Plains, says Freddie Lamm, Kansas State University agricultural engineer and irrigation researcher in Colby, noting that much success has been seen with cotton.
While initial costs are 40-50% higher than center pivot systems, growers can expect to see those costs paid back within two to five years, thanks to better water-use efficiency and lower irrigation energy bills.
Anthony’s ground outside Lexington, Neb., is part of that shift to drip. It’s paying off. With conservation in mind for years, Anthony’s 50-50 corn-bean rotation is 100% no-till. Residue left over from harvested crops help hold precious precipitation that barely approaches 20 in. annually.
The land includes some odd-shaped fields that aren’t practical for sprinkler systems. The gravity-fed furrow systems yield 200 bu./acre for corn and 65 bu. soybeans.
“But we wanted to be more efficient with our irrigation,” Anthony says. “We were using too much water with the furrow system and a pivot wouldn’t fit the field. So we looked at the drip system.”
He installed his first drip system in the spring of 2006 using Toro Micro-Irrigation equipment. It relies on ¾-in. Toro Aqua-Traxxplastic drip tape, also called dripline, buried 15 in. underground. Water is fed to soil and root systems through small precise outlets, or emitters, spaced 24 in. apart.
The buried dripline is spaced 5 ft. apart on the 30-in. row cropping system, resulting in each corn row being about 15 in. from the nearest dripline. Water is funneled to the tape by a series of 6-in. submain lines. They are fed by 8-in. main lines, which flow from irrigation wells.
“We are able to keep our corn yields at about 200 bu./acre and our beans at 65 bu./acre,” Anthony says.