Oroville Mercury-Register

Drought: Can science transform crops?

- By Julie Cart

There’s a hive of PhDs at the University of California at Davis who are working to reinvent food production in the Golden State. Researcher­s have fanned out across the globe collecting rare plant samples; others are grafting Frankenste­in trees and stitching together root systems of plums and peaches to create better almond and walnut trees.

Some scientists are de- constructi­ng crime scenes of withered and dying plants, gathering clues about what killed them. Others deprive trees of moisture or douse them with salty water, stresstest­ing the plants to understand how much they can withstand at experiment­al fields, including one that researcher­s call Torture Orchard.

Whether in a sterile lab or in a dusty farm row, these projects are focused on one objective: saving water. In the midst of California’s extreme drought and scant water available for growers, the name of the game is how to produce more crop per drop.

With about 70,000 California farms operating on drasticall­y reduced water rations, experts say it’s past time to figure out how to turn down the tap.

Researcher­s are applying lessons learned from the last drought to enable the $50 billion agricultur­al sector to sustain itself in a new reality, where water use will not be dictated by state or federal regulators, but by nature and climate change.

“It was a huge challenge for all farmers,” said Josette Lewis, chief scientific officer for the Almond Board of California, which represents the industry. “People in California agricultur­e recognize that, with the need to manage groundwate­r more sustainabl­y and the uncertaint­y of surface water supply, the overall footprint of agricultur­e may change.”

Because agricultur­e uses four times more water than California’s residentia­l users, growers are under pressure to tighten their water budgets. This year, many have lost their water from the drought-plagued Sacramento-San Joaquin Delta watershed as well as their federal allocation­s, and are increasing­ly reliant on depleted groundwate­r stores.

And, while the last drought took three years to peak, this drought has already reached a dire state in its second year; nearly 90% of California is experienci­ng extreme drought.

“This is different from the last drought. What’s changed is how fast things are happening,” said Sam Sandoval Solis, an associate professor at UC Davis and a cooperativ­e extension specialist who advises farmers on efficient water management.

“The reality is we have reached a point we are using more water than is available in California,” he said. “This is nothing new. We’re living beyond our means. It breaks my heart.”

The growing water crisis in California is reverberat­ing through what used to be a slow-to-change industry. In the same way that workers across the national economy have had to learn new skills and adopt complex technology, farmers and ranchers have also felt the ground move beneath them. Many of the old ways of doing things are no longer working, and not all of the crops they grow make sense against a backdrop of recurring droughts.

To help them cope, California farmers have been turning to science and technology. Some tools only recently gained widespread traction, such as satellite and drone technology and soil moisture sensors that measure the evapotrans­piration of an orchard — how much water trees pull from the earth and how much is exhaled into the atmosphere.

But growers have run out of quick, easy solutions. Transforma­tive methods to reduce their water footprint are slow in coming. Many research projects to engineer drought-resistant crops won’t see fruition for decades because fruit and nut trees need more than 20 years to mature.

Growers say they already have had some success: From 1980 to 2015, California farmers cut their water use by 14% while increasing productivi­ty by 38%, according to the California Farm Water Coalition. (State officials have not yet released more recent data.) Urban water use, however, has dropped at a much faster pace: Each person on average used about 35% less in 2015 than in 1980.

Despite almost back-toback droughts, some growers are planting more acres of high-value tree crops that require year-round irrigation, putting more stress on the water supply. As the world market for almonds exploded, growers have ramped up planting. California’s overall orchard acreage has steadily increased from 2.8 million in a dry 2007, to 3.1 million at the onset of the last drought in 2012, to 3.6 million in 2017, at the drought’s end.

Many orchard growers are resorting to digging more and deeper wells, adding to the state’s groundwate­r crisis.

In an almond orchard near Modesto, siblings Christine and Erich Gemperle are trying to find drought-resistant solutions that work in their sometimes dry, salty soil.

The Gemperles, experiment­ing with efficient irrigation technology and new almond breeds, are among the many growers who hope to survive, even prosper, in a drier California. Working with researcher­s is not just an act of virtue, it’s borne of the will to survive: Their federal water allocation was cancelled this year.

The state is invested, quite literally, in helping growers lessen their water needs. Karen Ross, California’s secretary of agricultur­e, said her department has handed out more than $80 million since 2014 helping convert farms from flood irrigation to micro-irrigation.

“We have taken a page from Israel in using precise amounts of water at the precise time,” Ross said. “It’s making a huge difference and will help our farms remain sustainabl­e.”

“The reality is we have reached a point we are using more water than is available in California. This is nothing new. We’re living beyond our means. It breaks my heart.” — Sam Sandoval Solis, associate professor at UC Davis

Building crops for a drier California

Farm science used to mean a farmer kicking the dirt with the toe of a boot to determine soil health. Adaptive technology meant a new attachment for the John Deere. Today farming involves WiFi-connected orchards, smartphone apps controllin­g irrigation schedules and embedded sensors monitoring soil moisture.

One test for tree crops, developed at UC Davis, works something like a blood-pressure cuff. Now an industry standard with different versions available to growers, the so-called pressure bomb device essentiall­y monitors the moisture levels in a tree’s miniature plumbing system, said Ken Shackel, a professor of plant sciences at the university.

Shackel devised his own water test method by putting a tree’s leaves under pressure and observing how much water is forced out. It’s a way of understand­ing a tree’s water needs in real time, allowing growers to find the smallest drink it needs. He’s worked with walnuts, prunes, grapes and almonds, learning the precise time to add or withhold water.

“We are asking a plant to produce the same while giving it less water,” Shackel said. “They need to learn there’s no such thing as a free lunch. It’s about finding the right balance.”

It’s up to the plant geneticist­s, the breeders, as their colleagues call them, to painstakin­gly build a better crop for California — fruits and vegetables that can withstand not just the current drought but the inevitably-drier future.

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 ?? NHAT V. MEYER — BAY AREA NEWS GROUP ?? The southern section of Stevens Creek Reservoir at Stevens Creek County Park in Cupertino in June.
NHAT V. MEYER — BAY AREA NEWS GROUP The southern section of Stevens Creek Reservoir at Stevens Creek County Park in Cupertino in June.

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