Nebraskan farmers see potential in SDI
The ability to water odd-shaped fields, lower pumping costs and increase water efficiency in hot, droughty weather are things that come to the forefront in talking about drip irrigation with Gary Greving and Don Anthony of Nebraska.
Both producers say for the past two years their subsurface drip systems have served them well by keeping pumped water out of the wind and heat, and both say the systems work well with their center-pivot sprinklers.
Greving farms about 1,100 acres near Chapman, Neb., and runs seven pivots. He also has about 40 acres of subsurface drip taking water to pivot corners and a pie-shaped area behind some of his farm buildings.
In this year’s drought and last year’s very hot and dry summer, Greving says he’s estimating a 2- to 5-bushel improvement in yields on his seed corn growing on SDI, and 5 to 10 bushels more on beans over the system.
• With declining water supplies, Nebraskans use SDI to maintain irrigated acres.
• Improving water use and pumping costs carry some sticker shock.
• Subsurface drip is suited for niche areas, even in broad-acre farming.
“This year I wish I’d had it on every acre,” Greving says with a laugh. But he’s quick to point out that the cost of installation of SDI is high — particularly on small plots, where it’s not uncommon to spend $3,800 to $4,200 per acre to bury the drip lines 16 to 18 inches deep on 60-inch centers.
Greving’s system is based on a drip line with emitters at 24-inch intervals and wells capable of running 700 to 1,100 gallons per minute.The Chapman producer says this year his pivots applied 24 to 26 inches of water, while the SDI system soaked on 12 to 14 inches of water.
Near Lexington, Anthony, a 30-year veteran of irrigation, has about seven years of SDI experience under his belt, and says he’s saving about 25% on water and energy compared with his six pivots. Anthony operates a 1,300-acre 50-50 corn bean rotation and has about 280 acres in SDI in corners and three 80-acre rectangles.
“I’ve not noticed yield differences,” he says, but the energy costs and water use are improvements. Anthony says the SDI allows him to “play chicken with the weather” and sometimes take advantage of rainfall that he might not otherwise be able to.
“It takes three days to complete an irrigation cycle and more than two weeks for the gravity fields to water. With SDI, I can apply a small amount of water quickly to avoid plant stress and wait longer for the rain. And if the rain doesn’t come, I can go back in and apply more drip quickly to finish up. If the rain does come, I’ve saved myself an irrigation application.”
The Lexington grower has also used SDI installations to keep all of his land irrigated despite dwindling water supplies.
“Since irrigated land has higher value, I’ve used the SDI acres to avoid a balance sheet devaluation of my assets,” he explains. Also, in Nebraska, land coming out of irrigated status cannot be placed back under irrigation later.
Since he is installing SDI on larger fields than Greving, Anthony reports installation costs of between $1,600 and $1,850 per acre.
FARMING FLEXIBILITY: Don Anthony, Lexington, Neb., uses SDI acres to wait out rains, and enjoys roughly 25% lower pumping costs and water use on those fields.
DRIP ADVOCATE: Gary Greving, Chapman, Neb., says his SDI corners are producing more in the hot, dry conditions of 2011-12. His system uses a drip line with 24-inch emitter spacing buried 16 to 18 inches deep.
This article published in the November, 2012 edition of IRRIGATION EXTRA.