Turning less water into better wine

This year’s limited rainfall – 4 inches less than last year, only a third of the annual average – is a reminder of how important agriculture is to Sonoma County, and the critical role of water in economic health. It’s not all about wine, however: Though wine grapes are the county’s primary crop, other agriculture includes dairy, livestock and poultry, sheep and lambs, even vegetable farming, grain and a significant apple industry.

One of the Valley’s largest grape growers is Sangiacomo Family Vineyards, who own or manage 1,200 acres in the county. For decades they have grown for important area winemakers, though it wasn’t until 2016 that they started producing wine under their own family label. It didn’t take long to succeed: Their 2018 Sonoma Coast Chardonnay won the white wine Best of Show at the North Coast Wine Challenge in 2020.

Given the scale of their operations – 14 vineyards, 1500 acres in the Sonoma Valley, Carneros, Petalulma Gap and Sonoma Coast appellations – water management is a key component of their vineyard best practices. In a previous interview, Mike Sangiacomo pointed out that water conservation is not an add-on to traditional vineyard management practices, but “part of the viticulture process. How you’re going to prune it, how you’re going to manage the canopy, how you’re going to irrigate it.”

Among the high-tech tools that Sangiacomo and other area vineyard managers use are soil moisture sensors, known as “neuron probes,” that measure the quantity of water in soil and transmit that information to an app.

“We definitely reduce our water use, just by being more diligent about using it where it’s needed,” Sangiacomo told the Index-Tribune this week.

A vineyard may be divided into smaller sets to allow for targeted water application where it’s most needed. Sam Coturri of the family-run Enterprise Vineyards, founded by his father Phil Coturri, manages about 900 acres in all, including fields in development or currently fallow. He said, “Several years ago we began installing dual irrigation systems in all our vineyards – a main irrigation line and a secondary line that allows us to water the parts of the vineyard under greatest stress.”

Soil moisture sensors, said Coturri, provide the best measure of that stress. “In the course of last few years we’ve probably reduced water use by over 30-plus percent per site,” said Coturri, using targeted watering through secondary lines and even hand watering at times. “Dual irrigation allows us to reduce our water use but still maintain vine health.”

Even in the peak of the growing season, said Coturri, it’s almost unheard of to water daily. And like many farmers, they’ve found that a longer period of “deep watering” helps the plants more than short, frequent irrigation.

That’s one of the key philosophies behind “dry farming,” a primarily European method of vineyard management that produces densely flavored grapes by “stressing” the vines, forcing them to grow a taproot deep into the soil.

Dry farming has a handful of adherents in Sonoma, and one of the most notable is Will Bucklin, of Glen Ellen’s Old Hill Ranch. He said he’s found tap roots 15 feet deep from his 130-year old vines, and has heard anecdotally of roots showing up in the construction of wine caves 40 or 50 feet deep.

“Simply stated, dry farming is the absence of irrigation, but it is really much more complex,” he said. An appropriate soil, well-spaced vines, a phylloxera-resistant rootstock and deep and frequent tillage, turning the soil to break it down into what he calls “dust mulch.”

“In talking to some people, I’ve been flabbergasted at the amount of irrigation people use,” said Bucklin. “I was aghast.”

“One of things that those of us who have old vineyards believe pretty strongly is that these vineyards exist because they’re dry farmed,” Bucklin said. “They have a much more resilient capacity to deal with the vagaries of Mother Nature. Most irrigated vineyards don’t last more than 20 or 30 years before they’re replaced.”

He recalls a 100-degree-plus heat wave in 2006 that wasted much of his vineyards, and he feared the dry-farmed plants would not survive – they wilted and their leaves became paper-thin.

“I thought we were going to lose the crop. Distraught, I decamped to a friend’s near the coast to drink beer,” he wrote in a blog post on his website, buckzin.com. But when he checked on the plants the next day, it was the old vines that recovered, and survived; the young plants were lost.

Much of Bucklin’s 40-acre property on Old Hill Ranch Road – across the highway from his mother and step-father’s (Anne and Otto Tyler) Oak Hill Farm – is now largely turned over to dry farming, with an emphasis on the art of field blends: a variety of grapes growing in a single vineyard, harvested together and co-fermented.

When asked if a field blend is a viable way to cope with low-water years, he answered without hesitation. “I do believe in it strongly, and I believe it makes better wine – I don’t think irrigation is a great way to make quality wine,” he said.

His self-described “curmudgeonly” approach to dry farming gains support from more established quarters. A recent UC Davis study “shows that vineyards can use 50% of the irrigation water normally used by grape crops without compromising flavor, color and sugar content,” according to Western Farm Press. That apparently holds true for traditionally planted commercial vineyards as well as older small-scale vineyards farmed like Bucklin’s.

His watering regimen has grown simpler over time. “My management strategy now is to do long, deep waterings twice annually,” thereby keeping the plant healthy but forcing the roots down deep into the soil where the water remains.

That’s true of Enterprise Vineyards as well. “We don’t necessarily farm for quantity, we farm for quality,” said Coturri. “By and large not using a ton of water is one of the ways you accomplish that.”

He pointed out that, given the premium wine market they serve, “even when yields are down like they are this year, it doesn’t drastically affect our business.”

Yet Coturri recognizes that it’s not all about the bottom line, or even better wine. “As farmers and citizens of Planet Earth, you have to be concerned about climate change, drought and where water comes from to sustain our lifestyle.”

To contact Christian Kallen, email christian.kallen@sonomanews.com.