Dairies, ethanol plants threaten groundwater supply
Agriculture is booming on the Texas High Plains, but the prosperity may be short-lived. The Ogallala Aquifer, the region’s primary irrigation water source, is receding fast, and experts predict the demand for water will exceed the available supply in 10-20 years.
“It’s a huge issue,” says Vivien Allen, forage agronomist at Texas Tech University in Lubbock. “You can’t be out here and not be pas- sionate about it, because it’s writing the whole future of this region.”
Allen is project coordinator for research comparing the water-use efficiency of various cropping sys- tems. Begun in 1997, the work has found that systems that include for- ages, especially warm-season perennial grasses, can save signifi- cant amounts of water.
In the last five years, however, dairies have moved into the region in a big way. About 485,000 dairy cows are now in an area that extends just across the borders of New Mexico and Oklahoma, and that number is expected to double in the next four to five years. The dairy expansion, along with five planned ethanol plants, makes saving the aquifer an ominous challenge, says Allen.
Two things that need to happen, she’s convinced, are for the dairy growth to end and for existing dair- ies to find less-thirsty alternatives to corn for silage production.
Said to be the largest contiguous area of intensive agricultural produc- tion in the world, the Texas High Plains encompass most of north- western Texas, including the pan- handle. The region currently produc- es 20-25% of the total U.S. cotton crop, about 25% of the fed cattle and is rapidly becoming a major dairy area, as well.
“About 40% of the economy of this region comes from agriculture,” Allen points out. “Agriculture is what it’s all about out here.”
Without irrigation, however, much of that revenue would be lost. Irrigators there pull water from the southern end of the Ogallala, a vast underground reservoir that stretches northward to the Dakotas. Once thought to be an inexhaustible water supply, the aquifer is dropping by almost 1’ per year in the region, and agriculture gets most of the blame. Roughly 95% of the water pumped is used for irrigation, says Allen.
According to her, the problem was identified in the 1970s, when farmers discovered that their irrigation wells were pumping less water than before. They began adopting more efficient irrigation methods, such as low-energy precision application (LEPA) and subsurface drip systems. That saved vast amounts of water, but as more and more wells were drilled, the gains were erased and the drawdown resumed, she reports.
Modern irrigation systems are 95% efficient, so future water sav- ings will have to come from other means. Allen says forages will play a key role. Interest in grazing is on the upswing, with cattle spending less time in feedlots and more time on grass. Cow-calf operations also are increasing in number. Perennial grasses suck up much less water than row crops, and those opera- tions are “holding right in there with cropping systems” in terms of profit- ability, she says.
Her research team has shown that integrated crop-livestock sys- tems use less water and nitrogen fertilizer than monoculture cotton, and also are more profitable at yields representative of the area. That is being verified in a $6.2 mil- lion demonstration project compar- ing water use and economics of vari- ous cropping systems at 26 sites owned by 21 producers.
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Funded by the Texas Water Development Board with money secured by a bill sponsored by Sen. Robert Duncan, the project involves researchers from Texas Tech, Texas A&M University, USDA and other entities, plus a nine-member producer board. The eight-year project just completed its third year.
Rick Kellison, a producer from Lockney, TX, is project director. He says detailed records are kept on various crops, ranging from monoculture cotton to forages for livestock. At the end of each growing season, growers get an economic analysis for each field, showing the net return per acre.
“We also report to the grower how much money he’s getting per acre-inch of water,” says Kellison. “It gives him a value of what he’s selling his water for.”
The most significant finding so far, he says, is the amount of water and money that can be saved by growing forage sorghum instead of corn for silage. Most of the new dairies moved from areas where corn silage is king, so silage corn acreage has been skyrocketing. Corn uses as much as 50% more water than the fully irrigated cotton it usually replaces.
But Texas A&M research, verified in the demonstration project, shows that some newer sorghum varieties can match the yield and quality of silage corn on 40-50% less water.
“So sorghum is more profitable,” says Kellison. “We think we can make a major impact if we can get this story told both to the dairies and to the growers.”
“That’s a step in the right direction, but it’s not going to get us to a sustainable level of water use,” adds Allen, and Kellison agrees. Both worry that continued dairy expansion will negate all water conservation efforts. Kellison points out that it takes 6,000 acres of irrigated cropland to feed a single 3,000-cow dairy – about 2 billion gallons of water per year.
Attracted by the region’s low human population and inexpensive land, the dairies moved in with encouragement from municipalities wanting to bolster a sagging rural economy. Kellison says the dairymen he knows are sophisticated, knowledgeable businessmen who don’t want to cause problems.
“But I don’t know that they got all the information they might have needed before they relocated here as far as the amount of water that was available,” he says.
Allen believes the ethanol plants are a mistake, too. They’re being built largely to process corn shipped in from other states. Much of the corn consumed by regional feedlots has traditionally come from the Midwest. But high corn and fuel prices are testing the economics of shipped-in grain and encouraging local production. With three nearby markets – dairies, feedlots and ethanol plants – she fears the transition from cotton to corn will continue.
“It’s pushing the incentive in the wrong direction,” says Allen. “We’ve got to have incentives to save water.”
While agriculture’s future on the Texas plains looks cloudy, Allen sees reason for optimism in the trend back to grazing. If the dairy expansion can be curtailed and enough land can be put back into grass, it might save enough water to permit some cropping to continue indefinitely. But she foresees it being limited to the best land and the best crop genetics, using the most efficient irrigation systems.
If the region is able to solve its problems, Allen figures it’ll be the “poster child” for other areas facing similar situations.
“The issues of water, and now energy and water, go hand in hand,” she says. “And the issues are so profound out here, if we can find solutions, we’ll be the place the rest of the world looks to for answers. But we cannot continue as we are right now; it isn’t going to happen.”