Southern Plains farmers understand the challenges they face to continue irrigating crops.As populations grow, demand for water increases. As aquifers continue to decline, wells that once produced more than enough water to irrigate season-long can't keep up. Soaring energy costs make efficient water use an imperative.
“We're running out of water,” says Doug Hlavity, a Lubbock County, Texas, farmer and one of three panelists who discussed efficient moisture management at the recent Southwest Crops Production Conference in Lubbock.
Joining Hlavity were Mike Henson, a Hockley County farmer, and Shelby Elam, who farms in Gaines County. Among the three, they've tried everything from row irrigation, conventional center pivots, LEPA irrigation, sub-surface drip irrigation and a smattering of dryland acres.
They've also tinkered with scheduling techniques, crop/fallow mixes, and planting fractions of a pivot circle to concentrate available water.
They say solutions to many of their problems, including disappearing water tables and high energy costs, will come from making more pounds of crop with the same amount or less water.
I put in my first pivot in 1991,” says Hlavity. “I've added one or two a year ever since. Recently, I added three fields of drip irrigation and I still row water about 500 acres.”
He says not all his land adapts to center pivots. “Anywhere it's flat, I install a pivot,” he says.
He's trying to use drip to take advantage of weak water sources. He tried his first drip system in 2000 in a field with 3 to 3-1/2 gallons of water per acre. “I used a stripper variety that first year and made 1,000 pounds per acre. I was disappointed. I got hailed out the next year, but in 2002 I planted a picker variety and made from three bales to three-and-a-half bales per acre.”
He said picker varieties under a sprinkler system produced 1,000 pounds per acre.
“Drip irrigation takes more management than a pivot,” he said, “and we don't necessarily use less water. In fact, I'll irrigate from seven to ten days longer with drip systems.”
Hlavity says water is the most critical factor in cotton yields. “I work closely with folks from the Conservation District to check soil moisture and determine how much rain or irrigation I need to fill the profile.
He uses the district's potential evapotranspiration system (PET) to help schedule applications.
That system helped him determine last year that he used more than 35 million gallons of water. “It was eye-opening to see how much water I used,” he says. “But I made more cotton.”
Elam admits to an inclination to “try everything once. I'm always looking for something new. I even tried vegetables and got that out of my system.”
He's farming with seven center pivots and fears he's running out of water. He's tried various crops in rotation with cotton to conserve water. “I run some cattle on wheat in the winter and have tried hay grazer and fallow” to stretch available moisture,” he says.
He's interested in drip irrigation but says the expense “makes me a bit nervous. But I've seen systems close to me and the results have been impressive. I think conservation tillage and drip irrigation might work together.”
Henson says most of his water sources “are weak. In one place I have ten wells to run a pivot. I've tried to cut back on water demand and planted peanuts under half a circle.”
He said water and financial considerations convinced him to try peanuts. “Cotton prices were low and we were selling what little water we had awfully cheap.
“I cut back on water use by not farming a whole circle. In some cases, I plant wheat and graze it. I'll cut it for grain if I get enough rain and then I rotate the next year. I get better yields by planting half circles. I can do that with drip, too.”
All but three of his center pivot systems are LEPA and he plans to convert those as soon as possible. “I'm doing all I know to improve water efficiency,” he says.
He installed a drip system two years ago, “trying to maximize cotton production from the gallons of water available to irrigate.
“Drip irrigation allows me to do that if I manage the system right. I get more production from a gallon of water.”
Hlavity says he's switching to more efficient irrigation as he can. “I'm not taking pivots out and installing drip systems,” he says, “but I do look for places that drip fits.”
Henson put in 50 acres of drip in 2001 and another 50 last year. Like Hlavity, he was a bit disappointed with his first crop, only 950 pounds per acre.
“But I got it in late and did not get the proper fertility.” He also questioned his variety choice.
“Last year I had a better fit and made 1,420 pounds per acre. He says drip irrigation, with potential for more than three bales per acre, may require more fertilizer. “I got my micros down last year.”
He's taking advantage of poor water resources. “With drip I can make three bales per acre with three gallons of water per acre. I can't make that with a pivot.”
He saves labor and other inputs by concentrating resources on fewer acres.
Hlavity says top yields require as much or more water than a pivot. “I'll need a rain to germinate the crop and I might not start irrigating as soon as I would with a pivot, but I'll water more, even after a one-inch rain. And I may go seven to ten days later than I would with pivots.”
He agrees that a three to five bale goal demands more inputs. “But with drip, that's attainable with a limited water source.”
He figures pivot systems are about 80 percent efficient. “Drip is close to 100 percent. I can make more pounds with the same amount of water.”
Energy costs may influence irrigation decisions this year.
I may not cut back because of energy costs,” Elam says, “but I'll be more keenly aware of the value of water.”
Henson changed last year. “In the past I pre-watered cotton from March 15 until April,” he said. “I shut it off before planting. Last year I ran the pivot one time before planting to wet the seedbed. If the crop sprouted, that was all I did; if it was slow to emerge, I ran the pivot again applying 1-1/2 to 2 inches of water. I used to apply 12 inches. With diesel and electricity prices going up again, energy cost will influence what we do.”
Farmers can expect a lot of influences, says Scott Orr, High Plains Underground Water District Number One. Orr, panel moderator, points out the crucial need to manage water more efficiently. “Currently, agriculture accounts for 95 percent of water use from the Ogallala aquifer,” he says. As populations and water demand increase, agriculture will be pinched. “Just think, the number of city dwellers is quite large and the number of farmers is small.”
He said irrigation improves yield and profit potential but buying and maintaining systems can be costly.
“Adequate water, affordable energy, crop mixes, and commodity prices will affect irrigation decisions,” Orr says. “A farmer's experience also influences his options.”