California’s dry farmers grow crops without irrigation

SAN JUAN BAUTISTA — Jim Leap fondly recalls the first Early Girl tomatoes he grew at UC Santa Cruz’s farm in 1990. Sweet and bursting with flavor, they were raised without a single drop of irrigated water.

Nearly three decades later, he remains deeply committed to “dry farming” — forsaking modern irrigation and relying on seasonal rainfall to grow tomatoes, winter squash, potatoes, dry beans and corn on the 4-acre San Juan Bautista farm that Leap and his wife, Polly Goldman, have owned for eight years.

“What motivated us to dry farm was the environmental ethic,” Goldman said. “We are not using city water or groundwater.”

As California gets hotter and drier because of climate change, Leap, Goldman and other members of this small but brave band of farmers predict that dry farming and other water-sparing techniques will become more popular in the Golden State.

While unfamiliar to many consumers, dry farming is an age-old practice that entails carefully managing soils to lock winter rainfall into the top layers until it’s time to begin growing crops during the spring and summer. As little as 20 inches of rain — roughly the same amount that the Central Coast receives each winter on average — can sustain crops in the months without rainfall, with no need to add any extra water.

The strategy has been used for generations by grape and olive growers in Mediterranean countries such as Italy and Spain. It was also common in coastal California through most of the 19th and early 20th centuries.

But practices changed as farmers got better at extracting water from under the ground. Yields boomed, and our food supply became more reliable. And so did our reliance on groundwater.

Today, many of the state’s water basins — particularly in the Central Valley, the state’s agricultural hub — are so overdrawn that they’re unable to replenish themselves.

California’s 2014 Sustainable Groundwater Management Act is aimed at ensuring that local and regional agencies better manage the amount of water pumped from wells. This means that groundwater supplies in the future are likely to be limited for farmers, who account for about 80 percent of California’s water consumption. And scientists predict that intense and frequent droughts caused by global warming will likely tighten water supplies further.

In some parts of California, growers such as Stan Devoto already see dry farming as a necessity.

“It is the way we have to farm in western Sonoma County if we’re going to grow apples,” said Devoto, a dry farmer who owns a 25-acre apple orchard in Sebastopol.

"I can literally count on one hand the growers that have adequate water to irrigate the orchards,” he said of the area, where farmers have long dealt with declining water levels and salt water creeping into freshwater basins.

But not everyone can dry farm, and not all crops can be dry farmed. It works best in certain climates and soil types.

The best-suited regions are those with clayey subsoil that experience morning fog and mild summer afternoons, with temperatures that rarely exceed 90 degrees.

“In the Central Valley, it’s really challenging,” said Rachel Long, a farm adviser at the University of California Cooperative Extension. “It doesn’t rain enough, and the temperatures are in the 90s and 100s.”

Also, fewer plants can be grown per acre, making dry farming less lucrative than conventional farming.

“It’s tricky and takes a lot of experience,” said Leap, 63.