Water Worries
By John Maday, Editor, Bovine Veterinarian May 13, 2015
In early April 2015, California Gov. Jerry Brown stood on a mountainside in the Sierra Nevada range and declared a first-ever set of statewide water restrictions. To drive home the urgency of the situation, Brown made the announcement from a location that dramatically illustrated the lowest Sierra Nevada snowpack in 65 years. “Today we are standing on dry grass where there should be 5 feet of snow,” he said. “This historic drought demands unprecedented action.”
Water has been near the top of the headlines lately and will continue to generate debate as the drought in California and much of the West reaches unprecedented proportions. And as water sources turn dry and municipalities claim a larger share of the resource, agriculture will need to adjust.
The California drought also serves to illustrate how, when water becomes scarce, agriculture takes the heat from an urban population disconnected from farming and the requirements of food production. To some, the issue is one of “farmers making profits while our lawns turn brown.”
Water and beef
Water is, of course, critical in beef production, but the volume used is commonly overstated.
You’ve probably encountered the claim, often parroted by anti-meat groups, that production of 1 pound of beef requires from 1,800 to over 2,000 gallons of water. Jude Capper, PhD, a livestock sustainability consultant, looked at the origins of that exaggerated claim. She found the figure originally came from the Water Footprint Network, a group of water analysts who used outdated information. The group, she says, based their estimate on a beef animal needing three years to grow to slaughter, producing 441 pounds of boneless beef. Based on average yields, that’s a 588-pound carcass weight and 948-pound live weight.
In reality, Capper points out, typical U.S. production systems finish cattle weighing approximately 1,300 pounds at slaughter, with 806-pound carcasses and 605 pounds of boneless beef. And they do it in an average of about 450 days, not 1,095. Water use varies but, in reality, probably averages less than one-third of that 1,800-gallon figure. And most importantly, water use for beef production has been declining for years.
While on the faculty at Washington State University, Capper conducted an analysis of resource use in beef production, including water, from 1977 through 2007, which was published in the Journal of Animal Science. Her analysis showed water use in U.S. beef production during that time declined 12 percent.
More recently, Kim Stackhouse-Lawson, PhD, director of sustainability research for NCBA, oversaw a checkoff-funded lifecycle assessment (LCA) of beef production, detailing all the inputs and environmental impacts involved in putting beef on the table. The initial LCA covered the years from 2005 through 2011 and will serve as a baseline for measuring progress in sustainability. The LCA data showed a 3 percent reduction in water use between 2005 and 2007. You can access a summary of the study online at beefresearch.org.
Stackhouse-Lawson and Capper say most of the reductions in resource use in beef production come as a result of improvements in production efficiency. In Capper’s research, for example, the number of beef cattle in the United States declined by 30 percent between 1977 and 2007, but the volume of beef produced per animal increased even more, resulting in an overall 13 percent increase in beef production. Improvements in genetics, reproduction, health and growth-enhancing technologies make beef production more efficient.
Capper says, for example, if we use growth-enhancing technologies such as implants, ionophores and beta agonists where appropriate from the stocker stage onward, the improved productivity can save 22,722 gallons of water per 800-pound carcass.
Stackhouse-Lawson notes that irrigation of feed crops and pastures accounts for about 95 percent of water use attributed to beef production. Continued improvements in crop yields and genetics for drought resistance, along with more efficient irrigation technology and agronomic practices, result in more feed produced per gallon of water.
Shifting patterns
The water-use issue is real though, and evidence points to long-term shortages of water in key agricultural areas.
The recent National Institute for Animal Agriculture (NIAA) conference focused on the theme of “Water and the Future of Animal Agriculture.” The program kicked off with a presentation from hydrologist Jay Famiglietti, PhD, a professor of earth-systems science and civil and environmental engineering at the University of California-Irvine, and the senior water scientist at the NASA Jet Propulsion Laboratory at the California Institute of Technology.
Famiglietti and NASA scientists have spent 30 years developing satellites, monitoring systems and computer models for tracking and predicting water trends. In 2002, NASA launched a pair of satellites known as the Gravity Recovery and Climate Experiment, or GRACE. The two GRACE satellites, orbiting 310 miles above the earth, act as a kind of scale, measuring changes in the volume of water in a region by sensing subtle changes in gravitational pull.
Through these studies and others, Famiglietti estimates total water storage in California has declined 8 trillion gallons per year over the past three years. According to an article on the GRACE website, High Plains aquifers have lost a volume of water nearly equal to that in Lake Tahoe over the past decade.
Overall U.S. water supplies have declined since 2002 in much of the West, Southern Plains and Southeast. In California, with the ongoing drought persisting and surface water mostly depleted, the state is shifting toward nearly 100 percent reliance on groundwater, Famiglietti says, which in some cases is not renewable or takes many years to recover. Globally, groundwater accounts for about one-third of all water withdrawals.
Using data from the GRACE satellites, Famiglietti says, scientists have noted a trend in which California groundwater recovers somewhat in years when surface water is available and declines when surface water is depleted. Over the long term, though, the declines are greater than the recovery in wet years.
Changes in climate patterns and water cycles generally have resulted in wet regions around the world getting wetter and dry regions getting dryer, Famiglietti says. In some cases, he says, we might need to shift some types of agricultural production away from areas experiencing long-term water shortages into areas with more sustainable supplies. A video of Famiglietti’s presentation is available on the NIAA website at animalagriculture.org.
Ag takes heat
When Brown announced the statewide water restrictions in California, he had a bit of good news for the state’s farmers and ranchers. Noting that agriculture already had borne the brunt of the drought, with hundreds of thousands of acres left fallow and thousands of farm workers out of work, his executive order mostly exempted agriculture from the new restrictions. Instead, the policy focused on residential lawns and landscapes and other large areas of irrigated grass such as golf courses, campuses and highway medians. The new rules will require farmers to report more water-use information to state regulators and submit drought-management plans as a means of cracking down on illegal diversions and waste.
That action quickly generated criticism and protests from environmental groups and anti-meat activists intent on driving “Big Ag” and livestock production out of the state.
Changing the dialogue
Famiglietti believes that for agriculture to remain productive, we need to change the dialogue on water and shift away from the “us versus them” conflict between agriculture and other users that tends to emerge when water supplies become scarce. We need better-defined processes for deciding how to allocate water for various uses while learning to produce food with less water, he says.
Stackhouse-Lawson agrees, noting that as long as people need to eat, agriculture will use water. Good stewardship will involve seeking continuous improvement in water conservation and strategic water allocation across production chains.
A key point, Stackhouse-Lawson notes, is that water used in agriculture is not “used up.” The water cycle we all studied in elementary school still works. Water percolates into aquifers, it runs down streams into lakes and oceans, it evaporates and returns as precipitation. Changes in weather patterns and water usage can, however, deplete supplies in some areas while increasing supplies elsewhere.
As those changes occur, agriculture will need to adjust. “Producers have always tried to use resources in the most efficient manner,” Capper says, “but that will be ever more important as consumers become aware of water issues.”
Sidebar:
Conserving water on cropland
Jane Frankenberger, a professor of agricultural and biological engineering at Purdue University, is heading a five-year, $5 million federally funded project examining methods for capturing water on farms for crop use while reducing nutrients draining into waterways. The project, titled "Managing Water for Increased Resiliency of Drained Agricultural Landscapes," involves seven other universities and the USDA’s Agricultural Research Service.
The objective is to advance three innovative practices that can address the problems of crop loss from drought and the degradation of water quality from drained farmland:
· Drainage water management — Unlike conventional drainage systems, this practice conserves water by increasing its retention time in the soil profile, thereby delaying or reducing the draining of soil water.
· Saturated buffers — These store water within the soil of field buffers by diverting tile water into structures that raise the water table and slow outflow.
· Reservoirs — With this “capture and use” system, subsurface drainage water is diverted into on-farm reservoirs, or ponds, where it is stored until it is needed to irrigate crops.
Source: Drovers CattleNetwork
