Drought forces Sonoma County farmers to make adjustments to crop plans
While Sonoma County supervisors declared a drought emergency on Tuesday, local farmers already had been taking action as they grapple in an era with much less water for their crops than in previous years.
The results can be seen from the vineyards of the Alexander Valley to the pastureland of west county. There will be fewer grapes harvested than in a typical year, as vineyard managers have pruned vines and some acreage is likely to go unused.
Dairy ranchers are expecting plots of grassland will go brown earlier than usual, while others are selling a portion of their herd to better manage revenue. Vegetable growers are focusing on crops such as peppers that can be grown quickly for more profit.
It’s no wonder, because with spring in full swing, the area is only at 38% of average rainfall since Oct. 1, the beginning of the rain year. Nearly 13 inches of precipitation has been measured so far at Charles M. Schulz–Sonoma County Airport, according to the National Weather Service.
Sonoma County Farm Bureau is issuing a best practices manual for agricultural sector to help its members adapt. The group also is conducting a survey of farmers on steps already taken, such as the number of acres unplanted this year due to less available water, said the farm bureau’s executive director Tawny Tesconi, who expects that acreage to be significant and demonstrate farmers’ water reduction.
The worsening drought conditions forced a balancing act that can be seen at area vineyards, where wine grape growers are monitoring the buds that have bloomed this spring on their vines. The grapes are the region’s most lucrative crop with a value of $356 million from last year’s harvest. That was nearly half of the 2019 value, since fruit was damaged by wildfires in 2020 and left on the grapevines.
A big worry for farmers during the remainder of spring is frost protection during chilly nights. Many grape growers use sprinklers that can coat the vines in ice during the night, keeping emerging buds at a constant 32 degrees and preventing harm to them. So far, there hasn’t been that much damage this year, but growers said that they will not be free of the frost threat until late May. Then the wine grape harvest typically kicks off in mid-August.
“The cold spring nights have caused many grape growers to be up in the middle of the night managing frost protection. The lack of winter rain is a big concern for all of our grape growers,” said Karissa Kruse, executive director of trade group Sonoma County Winegrowers. “We know that there is a looming drought and everyone is already looking at water conservation efforts.”
The lack of rain has posed problems at Munselle Vineyards in Geyserville. The farm has two reservoirs extremely dry and another one about half full because of the lack of rain, said Bret Munselle, a fifth-generation grape grower with 300 vineyard acres.
“We haven’t lost any vineyards yet to forest for lack of water, but I’m certainly nervous about it,” Munselle said.
With the threat of continued drought, Munselle said his family invested in wind machines to keep the air over the vines above freezing temperature.
“Twenty years ago we had zero. Now we got seven,” he said of the wind machines, noting there about 30 of them being used in a nearby portion of Alexander Valley.
“People are worried about water, trying to conserve water. Wind machines are an option,” Munselle said. “The technology on them is better than it used to be. They’re not as loud as they used to be and they cover more acres than they used to.”
Other growers are looking to grow less fruit. That can be accomplished by not farming certain vineyard blocks or cutting questionable grapes from the vine to give remaining bunches a better chance to make it through harvest. One hillside vineyard in Alexander Valley overseen by Bevill Vineyard Management offers an example of that since its nearby pond will not provide enough water for irrigation, owner Duff Bevill said.
Workers pruned the vineyard so there would be fewer fruit-bearing vines, which means less cabernet sauvignon grapes to pick in the fall. “There’s less leaves to transpire moisture, so the vines are basically pruned to become a smaller vine this year because we can’t water them,” Bevill said, noting that trucking in water to irrigate is not a cost-effective alternative.
Bevill’s crews also mowed off the cover crops between the vines so they wouldn’t have to compete as much for the limited rainfall this winter and so far in spring.
“We're dry farming the vineyard this year that’s never been dry farmed,” Bevill said, expecting the vineyard will yield about 50% of its average crop of grapes in the fall.