One of the main pillars of sustainability is implementing practices that will ultimately help create a more sustainable future, restoring the minerals and nutrients that have been lost and preserving biodiversity. When it comes to the stewardship of our land, let’s take a look at the how we manage and work the soils that grow our vines.
Soil is the support system for nutrients, biodiversity, water, and organic matter; all of which are essential for food (and vine) production. In agriculture, the primary resources used, water and soil, are closely linked. The soil is directly affected by the quality and quantity of water used.
With countless areas around the globe experiencing extended periods of drought, the topic of water conservation has become of increasing interest amongst both farmers and grape growers. What is old, is becoming new again, with the practice of dry farming being an option for many who tend to the vines.
What is dry farming?
It is a specific agricultural technique, practiced in typically arid regions, where crops (and in this case, vines) are cultivated without irrigation.
The idea of growing wine grapes without irrigation is less radical than you might think. In countries such as France, Italy, Spain and Germany, dry farming has been practiced for many centuries. It is even something that is built into their appellation control certifications. Most European countries will permit irrigation for newly planted vines, but in some instances, like in France, the watering of mature vines can lead to your certification being revoked. Even in California, grape growers relied on rain alone until drip irrigation was introduced in the 1970s. The grapes responsible for establishing Napa Valley as a world-class wine region during that time – from brands like Stags’ Leap and Chateau Montelena – all came from dry-farmed vineyards.
How does irrigation effect vine growth and the grape?
Irrigation keeps the roots close to the surface of the soil, training them to be more horizontal than vertical. Since the roots of nonirrigated vines do not obtain water from above the soil, they tend to sink deeper into the soil, below the topsoil, in search of moisture and minerals. Even in drought conditions, the vines can still find moisture from deep below the top layers of soil.
A vine that receives higher amounts of water will produce more stomata on the bottoms of its leaves. As a result the fruit will tend to have more sugar, ultimately leading to a wine that is higher in alcohol.
There are many good aspects to consider with dry farming, but when looking to implement and practice it, there are a few other factors that need to be considered. Location matters, as do soil and root-stock.
The most basic of these factors is rainfall (including snow melt).
- An area cannot receive more than 20 inches of rain per year for regular dry farming.
- When the rain falls is important. Rain in spring and summer is important because that is when you have flowering and fruit set. In areas that receive minimal rainfall during this time of year will need to relay on water that has been retained in the soil from winter rain.
Soil with moisture retention capabilities.
- Deep soils where vines can burrow down are important.
- Clay & sandy loam are great at retaining water.
- Sandy soils or heavily fractured soils do not work well.
- “Nothing is drought tolerant on shallow soils,” says Andy Walker, a professor at the University of California-Davis Department of Viticulture and Enology.
- George rootstock is a preferred rootstock for dry farmers due to its drought resistance and reduced yields.
- Riparian rootstock love water, but don’t have drought resistance.
Trellising, or lack thereof.
- Dry farmed vineyards are frequently bush pruned. This promotes smaller vines with less wood (which means it needs less water). It also allows natural shade for the vine while still having air flow. Vines need to be spaced further apart than in standard modern vineyards. Depending on the soil & rainfall, in the most extreme cases, this can vary from 32-120 feet. You see this in some areas of Spain, such as the Toro region, where the vines are spaced far apart in bush vines to get enough water to thrive.
Some grapes do better with dry farming than others.
- Vigorous grapes do best, because the reduction of vigor in dry farming just brings them into balance. That means that classic hot climate grapes like Zinfandel, Cabernet Sauvignon, & Tempranillo do well, but grapes like Pinot Noir do not. Barbera is considered one of the harder grapes to dry farm.
As the world population continues to grow and our climate evolving, it is becoming more important to build upon traditional practices, such as dry farming, alongside other soil management practices.
Try a Dry Farmed Wine!
Eyrie Vineyards Pinot Gris 2016, Dundee Hills, Oregon
“Incisive citrus and orchard fruit aromas are complicated by suave floral and smoky mineral flourishes. Juicy and sharply delineated on the palate, offering concentrated Meyer lemon, pear, and bitter quinine flavors sweetened by a subtle touch of honey. The mineral note comes back strong on a vibrant finish that shows outstanding clarity and tension.” 93 points, Vinous
Vintage notes from Eyrie Vineyards: The Pinot Gris ages 3-4 times longer than most, on its natural yeast lees and in the company of full malolactic. The result is textural suppleness to complement the acidity, and a surprising ability to age. The 2016 vintage started off with a warm, wet March, and continued with warmer than average temperatures throughout the spring summer. Fortunately, the extra water early in the year prevented the vines from experiencing drought stress in the summer. As we coasted through a warm summer, we prepared for a harvest more than a month ahead of what we’d consider normal. In September, just as harvest started, moderate temperatures moved in. With cooler weather, fruit ripened at a leisurely pace. This provided winemakers an unhurried opportunity to choose their fruit for perfect ripeness.