The New Water Misers—Farmers?

Agriculture uses most of the water supply, but researchers say growers have become increasingly efficient at irrigating crops.

(Photo: Justin Sullivan/Getty Images)

May 27, 2015· 1 MIN READ
Padma Nagappan is a multimedia journalist who writes about the environment, renewable energy, sustainability, agriculture, and biotechnology.

As urban Californians face mandatory water cutbacks and potentially huge fines for wasting an increasingly scarce resource, their ire has turned on farmers who use 80 percent of the drought-stricken state’s water supply.

Overlooked in the finger-pointing is that farmers are producing more revenues and more crop per drop thanks to new technology, according to Michael Cahn, an irrigation adviser with the University of California Division of Agriculture and Natural Resources.

“Water is starting to cost everyone more and more, so no farmer is willfully exploiting his supply or wasting it,” he said.

Cahn found that in the region surrounding Salinas, California, more than half the lettuce crop is grown using highly efficient drip irrigation. That has resulted in a 40 percent drop in water consumption by area farmers over the past 25 years.

By 2011, most tomato farmers had stopped flooding their fields with water and switched to drip irrigation that targets the roots of individual plants. That produced a 54 percent increase in water efficiency, while using similar techniques on much maligned almond trees led to a 33 percent rise in efficiency.

“Almonds use the same amount of water as wheat or lettuce, but almonds are in the ground the whole year, while lettuce is only in the ground 60 days,” Cahn said. “So lettuce uses about the same water as almonds would use in 60 days.”

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Your average suburban lawn, he noted, sucks up as much water as lettuce if it covered a similar-sized area. “We have a choice on how to use that water—to grow food or to water lawns and wash cars.”

Heather Cooley, director of the water program at the Pacific Institute, an Oakland, California–based research organization, said it would be a mistake to villainize farmers.

“There’s a tendency to see this as cities versus farms, but in reality we are all eating the food, not just us but others worldwide, just as we eat food grown elsewhere,” she said.

So, Why Should You Care? California grows nearly half the United States’ fruits, vegetables, and nuts and supplies 80 percent of the world’s almonds.

But Cooley noted that many farms still flood their fields and have yet to deploy new techniques to save water.

To that end, Cahn has developed a web app that helps growers schedule when they irrigate particular crops and use water most efficiently, given local weather conditions.

“The reality is it takes a lot of water to grow crops,” Cooley said. “When people say clearly ag is not sustainable in California, to them I would say with our current practices it’s not, but if we make improvements, we can definitely sustain a vibrant ag economy.”