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Commentary: UC Davis seeks practical solutions for water needs

Issue Date: March 4, 2015
By Helene R. Dillard
Helene Dillard
UC Davis Professor Helen Dahlke, uses a GPS device to record the location of a thermal infiltrometer, as part of a groundwater-banking project Dahlke is conducting in Siskiyou County.
Photo/UC Davis
The infiltrometer, measures the amount of water infiltrating the soil, as part of a groundwater-banking project Dahlke is conducting in Siskiyou County.
Photo/UC Davis

After another winter of below-average precipitation, California's water situation is severe and the short-term outlook is dire. But our situation is not hopeless. The drought's clear and present danger to California's agriculture and economy provides a unique opportunity to improve our state's long-term water management through cooperation, shared vision and science-based solutions.

Researchers at the University of California, Davis, College of Agricultural and Environmental Sciences are working with growers, industry and agencies throughout the state to find practical solutions. Here's a quick look at some of the latest developments.

Professor Helen Dahlke with the Department of Land, Air and Water Resources and her team are making headway with groundwater banking, where excess surface water during storms and flood releases is directed to select fields to serve as infiltration basins to replenish aquifers. Dahlke's team has begun a two-month test in an alfalfa field near the Scott River in Siskiyou County, applying water in various amounts to analyze soil saturation, infiltration rates, and whether the winter irrigation adversely affects the alfalfa.

The team hopes to launch similar projects in Orland in Glenn County, where many growers rely solely on groundwater, and in the lower Tulare River area of Tulare County. Groundwater projects with the Almond Board of California are also in the works.

River water for Central Valley farmers was reduced by one-third last year, and 425,000 acres of the world's most fertile land lay fallow. Are there practical ways growers can stretch water without reducing crop production, quality and yield?

Yes, according to results of a water-saving project in the Pajaro Valley of Monterey County led by Professor Samuel Sandoval Solis, a Cooperative Extension specialist with Land, Air and Water Resources. Sandoval's team identified steps that conserved 5,100 acre-feet of water per year without sacrificing crop quality and yield.

Sandoval's recommendations focused on optimizing irrigation, finding that line between applying too much and too little water. There are many variables, and our experts are helping remove the guesswork.

Example: UC Davis plant physiology professor Ken Shackel is part of a five-year experiment in Merced, Kern and Tehama counties to see how different irrigation levels affect almond yields. Shackel's team is applying 70 percent to 115 percent of recommended irrigation levels based on weather-station data, and monitoring orchards weekly. Two years in, preliminary data indicate yield may start to drop at about 90 percent. Stay tuned.

More growers are using pressure chambers, devices developed at UC Davis that measure a plant's water needs directly by gauging how hard a plant is working to pull moisture from the soil. Shackel and his colleagues recently developed an interactive, online tool to help growers interpret pressure-chamber readings. Meanwhile, Professor David Block with the Department of Viticulture and Enology and his team are designing a grapevine irrigation system that applies water based on each vine's individual needs.

Our breeders are developing new varieties of food and fiber that can thrive in dry, saline conditions. Department of Plant Sciences Professor Eduardo Blumwald is working to develop rice varieties that don't shut down in drought conditions, but rather continue to produce the nutrients necessary to make rice grains.

Plant Sciences Professors Jorge Dubcovsky and Jan Dvorak are mapping, isolating and cloning genes from the massive wheat genome, investigating critical stages of development. Dubcovsky's lab recently identified a region of a rye chromosome that, when introduced into wheat, increases yield and improves the water status of the plant under limited irrigation. Dvorak's lab is working to develop a novel, salt-tolerant forage crop that could be irrigated with poor-quality drainage water.

Viticulture and Enology Professor Andy Walker is breeding drought- and salt-tolerant grape rootstocks by optimizing root architecture to improve water-use efficiency.

A typical winery uses four to six gallons of water (after the grapes are harvested) to produce one gallon of wine, most of that used to wash equipment. At our new Jess S. Jackson Sustainable Winery Building, researchers are developing self-cleaning fermentors capable of recycling 90 percent of that water. The goal: affordable technology that uses one gallon of water to produce one gallon of wine.

Members of our food science faculty, including Professor Chris Simmons, are working with food processers, inspecting and analyzing every pipe and plant procedure to find inexpensive ways to save water and energy.

We're also helping Californians save water in their own backyards. At the UC Davis California Center for Urban Horticulture, experts such as David Fujino are providing information on irrigation management and drought-tolerant plants to reduce urban water use and prevent runoff from landscapes.

There's no one, simple way to deal with California's drought. But together, I know we can find long-term solutions for managing our vital, scarce water resources.

(Helene R. Dillard is dean of the UC Davis College of Agricultural and Environmental Sciences.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.

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