Berkeley Professor's Radar May Yield Better Wine Grapes

OAKVILLE, Calif.-The days of wine makers smashing grapes with their feet are a thing of the past. Today's winemakers use mechanical grape crushers, chemistry and-thanks to new research from UC Berkeley scientists-could be using radar technology to produce the next great vintage.

The new technology, which shoots radar beams beneath the surface of the soil, could give winemakers a more accurate view of their soil's moisture levels-a crucial factor for producing good wine grapes.

Currently, wineries gather soil moisture data by drilling holes and taking samples from several points throughout their vineyards.

But that data isn't always accurate. The wineries must predict the soil moisture of an entire block of vineyards-which can be as large as 4 acres-from only those few samples.

By contrast, the new ground-penetrating radar, developed by UC Berkeley scientists Yoram Rubin and Susan Hubbard, can accurately map soil moisture over multiple acres-which means better wine for your next dinner party.

"It's really some art and some science, and we're trying to bring more science into it," Daniel Bosch, vineyard technical manager for Robert Mondavi Winery.

The radar technology, originally used to locate utility pipes and other subsurface structures, first shoots a radar beam below the surface. The beam is then reflected back, bringing with it new information about what lies beneath the soil.

If the velocity of the radar beam returned to the surface is high, soil moisture is low. If the velocity is low, soil moisture is higher.

Rubin and Hubbard demonstrated the radar Wednesday at the Robert Mondavi Winery in Napa Valley, rolling the radar apparatus over the ground, collecting soil moisture data every 5 centimeters.

Wineries depend on this data to yield the best-quality grapes consistently over an entire vineyard.

Wine growing requires a delicate balance: The smallest grapes produce the most flavorful wine, so winemakers try to keep their vineyards as dry as possible in order to grow the tiniest grapes.

But if the soil is too dry, the grape vines will wither and die. If the soil is too moist, the grapes grow fat and flavorless.

"A lot is controlled by what's going on underneath the ground," Bosch said.

The ground-penetrating radar will help wineries predict when their soils will be driest, and will help growers adjust their irrigation to create optimum moisture levels.

Wineries armed with data from the new radar could know exactly how much moisture their grapes have been getting, and hence, exactly when they're ready for harvesting, Bosch said.

Both the increased quality of the grapes and the predictability of harvests "translates into a lot of dollars," Rubin said.

The Robert Mondavi Winery plans to use the radar in the future to check the data it already collected using the drilling-holes method, Bosch said.

Beyond wine growing, using the ground-penetrating radar could make agriculture more environmentally friendly, Rubin said.

With a more accurate picture of soil moisture, winemakers and other farmers could help prevent the spread of pesticides throughout the ground, he said.

And the technology could even spread beyond agriculture. The radar could save the government money by detecting the levels of moisture beneath paved roads and highways, making for easier maintenance, Rubin said.

In the meantime, Rubin believes his technology will at least spread in the wine-growing world.

"We have a tool that's pretty advanced," he said.

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