With water shortages spiking across the nation, concern that more irrigated acres will be needed to grow biofuel crops has started a water fight.
Several published scientific articles now suggest that expanding biofuel crops into regions with little agriculture, especially dry areas, could change irrigation practices and increase pressure on water resources.
The National Research Council, for example, reports that increasing biofuel crops in areas that require additional irrigation, such as the Northern and Southern Plains, is a "major concern." The International Water Management Institute says that if all national targets for biofuels production are met worldwide, an additional 74 million acres of land and 47.5 trillion gallons of water for irrigation will be needed.
Recently, a study by the U.S. Department of Energy's Argonne National Laboratory projects that water consumed by energy production (including biofuels, gas, oil and coal) will grow faster than any other sector. Within this energy sector, Argonne projects the single largest water consumer will be biofuels production specifically for the irrigation of energy crops, such as corn and soybeans.
Water consumption for biofuels production is projected to increase by 19 billion gallons per day between 2005 and 2030, according to Debbie Elcock, an environmental and energy policy analyst with Argonne.
"Most of this increase is for the production of corn-based ethanol," Elcock says. "It is more than double the amount of water projected to be consumed for industrial and commercial use in 2030 by the entire United States."
Irrigated or not? The National Corn Growers Association (NCGA) and the Renewable Fuels Association (RFA) say the key point to consider is whether the additional crops grown for biofuels really will be irrigated.
"Just a fraction of the corn grown today is irrigated, and most of that irrigated corn is not grown adjacent to the highest concentrations of ethanol facilities," says RFA's Matt Hartwig.
Most corn from fields that are under irrigation is fed to cattle in feedlot states, according to NCGA research.
Also, most studies blaming biofuel crops for draining water supplies do not take into consideration the new drought-tolerant corn varieties coming down the pipeline, explains Nathan Fields, NCGA's director of biotechnology and economic analysis.
"This is a difficult blame game," says Otto Doering, a Purdue University economist. "Either side can put the numbers together to fit their stance on water resources."
More acres, more water? There is no denying that high commodity prices and government mandates for biofuels have brought more land into corn production, with more than 19 million additional acres of irrigated corn planted in 2008 as corn moves to the fringes of the Corn Belt.
The overall spike in corn acres, however, is more a function of acres shifting out of cotton than more corn plantings in dryland regions, Fields says. Most cotton growers who shifted to planting corn don't use irrigation.
"This is a good economic indicator that if the market sends a strong signal for more corn on a short time frame, it will come from areas that do not need irrigation first," Fields says.
The question for the future of bio-fuels and water usage is whether production of inputs for ethanol will require irrigated corn, Doering says.
"If you bring in more irrigated acres, and you bring in total irrigated gallons used for corn, then that is a strain on our water supplies," he adds. "But you have to figure out where you attribute the demand for irrigated acres—is it biofuels, exports or cattle feed?"
You can e-mail Jeanne Bernick at firstname.lastname@example.org
- March 2009