Vineyardists Learn About Soil, Water Relationships
LENHARTSVILLE, Pa. — So what makes the perfect wine? The grapes? The vines? The winemaker?
All of these can contribute, of course. But so does the environment in which the grapes are grown, or the terroir, as some put it.
Xavier Chone, a French wine consultant, knows a little about terroir, having worked in Bordeaux, France, one of the places where the concept of wine terroir was born to describe the foundation of the unique wines found in Bordeaux and Burgundy.
Speaking to a group of winemakers and vineyardists gathered on Feb. 21 at Blair Vineyards, Chone talked about applying terroir concepts to make better-tasting, higher-quality wines in the Keystone State.
Chone defines terroir as the “sense of the site,” everything from the soils in which the vines are grown to the climate they are grown in.
“It really is something that is a big deal,” he said.
Considering the rain and humidity that accompanies Northeast summers, the climate part of the terroir equation is a challenge for vineyard managers in this region.
Still, it’s something Chone said can be partly overcome by understanding the relationships of soil and water, and how that affects a plant.
Vine water status, he said, is the “spinal cord” of terroir and something that needs to be known to understand if a plant needs water or doesn’t.
In places like California’s Napa Valley, growers can intentionally stress a plant to bring out what they feel are positive physiological changes.
Some growers use pressure chambers or pressure bombs, which are machines used to measure the amount of stress in a grapevine, so they can tell whether they should irrigate.
“Grape quality is always a matter of vine water deficit,” Chone said. “The best vineyards are actually water deficit.”
Controlling nitrogen availability, he said, can be an important factor when thinking about controlling vine vigor.
Too much vine vigor in red varieties, he said, can bring early grape ripeness and affect the taste of the wine.
In white varieties, such as Chardonnay, limited nitrogen availability can actually bring more finesse to the wine.
“It is a very big deal to control vine vigor,” Chone said.
Of course growers here can’t control the rain, and some years are worse than others. But understanding how water interacts with certain soils, he said, can go a long way to improving grape quality.
“I think they need to fine-tune, to adapt their soils and get the best understanding of their soil water holding capacity,” he said. “From that, manage the vineyard for the ones they are going to plant.
“It’s not like Bordeaux or California. They need to find their balance, and they will have better fruit,” he said.
Jim Law, owner of Linden Vineyards, which is in the Blue Ridge Mountains 65 miles west of Washington, D.C., has worked to understand his soils since the first vines were planted in 1985.
He grades his sites from A to F (A is excellent, F is poor) to gauge which sites are better for a given rootstock.
“When you talk about terroir, it depends on what you’re growing,” Law said.
Steep slopes are areas he prefers because of their ability to dry out quickly. Silty soils, he said, hold too much water and nitrogen.
Rain can be a struggle in the summer, especially on days when it is constantly humid and moist.
But getting a better understanding of his soils, Law said, has given him a way of placing his vines where they can perform best, even in the worst conditions.
“You put the vines in the best place where it can really express itself,” he said.
Summer moisture can lead to vines that are too vigorous, according to Mark Chien, viticulture Extension educator for Penn State. A lack of moisture is one reason growing wine grapes is easier in places like California and Chile.
But the concept of controlling soil moisture isn’t something vineyard owners around here should ignore just because they get more rain.
Chone’s “idea about controlling soil moisture or plant available moisture and the nitrogen in the soil is very important for us,” Chien said. “Just in terms of controlling the size of our vines.
“Where he works with some producers, they don’t have much soil moisture. Here, we have a lot, making it much more challenging,” Chien said. “It’s about getting the vine at the end of the season to ripen grapes instead of grow more leaves.”
Denise Gardner, Penn State’s Extension enology educator, said that while it’s a winemaker’s dream to produce terroir-driven wines, there is also the factor of giving customers the products they want.
“When we talk about things like this, it gives you the kind of hope that you’ll be able to do those kinds of wines later on down the road and really push for that higher quality,” Gardner said. “It’s challenging around here because of the weather conditions, plus you want something consumers will like and will rely upon. So it’s two very distinctive, conflicting battles, in that perspective.”
Rich Blair, owner of Blair Vineyards, which produces 5,000 cases of wine a year from 30 acres, said he’s dabbled with ways of decreasing the amount of nitrogen in his soils, including taking materials out of some of his soils.
Unlike neighboring farmers who look for ways to get water and nitrogen to grow plants, he said he’s always looking for ways to create water deficiencies to reduce vine vigor and improve quality.
Blair grows vines on two different sites — the home site, where the winery itself is located, and another site 10 miles south at a higher elevation.
Blair said he likes working in both sites, although the home site, he said, is better because of more sunshine. The sites have completely different terroirs, which he said shows up later in the wine.
“It takes in the site, so it’s site specific. It takes in the climate, precipitation, temperatures, locations of woods, streams, valleys, anything that can influence the temperature,” he said. “For us, terroir is also the soils, and so it’s really important to take a look at how everything comes together.
“My wines grown from there taste different than wines grown from the home farm with the same grapes,” he said. “It’s amazing how the influences of a site can influence the wine.”