Cattle feed production in the Western United States account for 32 percent of water use in those arid lands and irrigation of cattle feed crops is the greatest cause of water depletion for one-third of rivers in the West, according to a study published in Nature Sustainability.
The team of researchers investigated the West to find regions that approach or surpass the rate of water replenishment where rivers lose water flows and fisheries are harmed. Those locations around the US where crops are grown to feed cattle then had models developed that showed the impact of these crops on rivers.
Scientists found that irrigated crop production accounts for 86 percent of all water consumed in the western U.S. and of that, the largest portion goes to crops going for cattle feed, such as alfalfa and grass hay. This in-depth study not only looked at the supply and demand of water in the Colorado River basin but traced the use of that water from the field where hay is grown to the end user, the consumer.
The researchers offered a major way to address the issue, by having farmers fallow fields for a limited time in places where cattle-feed crops are grown — thus avoiding irrigation — to decrease pressure on some rivers, improve fish ecosystems and reduce water scarcity.