An Update on the April 21 Frost

I’ve been getting a lot of questions about the effects of last week’s devastating frost at Dodon, when no vine was left untouched, despite improved cold-air drainage in the low spots and the fans running in a futile attempt to bring warm air into the vineyard.

Many of our colleagues took even more desperate measures, such as scalping the ground with mowers, applying nutrients to disrupt nucleation and alter intracellular osmolarity, and using helicopters, open fires, and smudge pots, all of which can create air circulation. None of this worked. There was simply too much cold air. Only the vineyards along the Chesapeake and at 6-800 feet above a valley floor survived unscathed.

It was worse than it looked. As the highest and warmest spot in the vineyard, the Merlot in the first few rows of Block 41 along the driveway was the least affected, but even these vines showed signs of damage. We lost almost all the primary buds in the Chardonnay, Cabernet Franc, and Sauvignon. The Merlot, Petit Verdot, and Cabernet Sauvignon were not quite as far along, so a few primary buds had yet to break, but even these sustained severe damage.

Fortunately, grapevines have compound buds. Usually, only the primary buds emerge. These are the most vigorous and fruitful, producing shoots that bear two or more clusters. If the primary buds fail to break or are damaged by frost or other injury, secondary buds emerge within hours or days. Much of the green tissue in the vineyard now is the result of these buds. Sadly, they are much less fruitful than the primary buds, producing at most a single cluster.

It's much too early to know the full extent of the damage to the vintage. We won’t know this until fruit set in mid-June at the earliest, and even then, the growing season will bring many challenges. My best guess is that we can reasonably expect a crop of 30-40% of normal, about 12 to 15 tons of fruit or 700 to 900 cases of wine, most of which will likely go to white and rosé production. Some of our industry colleagues have already declared the vintage a complete loss, laying off workers in the process.

Because it takes vines several years to fully recover from an injury of this magnitude, the losses are likely to continue beyond 2026. The white vines first frosted in 2020 and again in 2021 and 2022 still haven’t returned to full productivity. We don’t know whether the ecological practices we use will alter this course, though it makes sense that healthy, well-nourished vines in a functioning ecosystem will heal faster than unhealthy vines planted in poor soil.

Fortunately, our business plan anticipates these events, so we’re likely to be fine in the long run, at least this time around. But the longer term is still unclear. We had never experienced a killing spring frost until 2020. They are now annual occurrences, adequately addressed by the cold drains, at least until now.

The underlying challenge is warming driven by fossil fuel combustion and outdated agricultural practices. Hotter winter temperatures trigger earlier bud break, extending the risk period. At the same time, atmospheric warming disrupts the polar vortex, allowing cold Arctic air to dip into temperate regions later in the season. The slowdown of the Atlantic Meridional Overturning Circulation (AMOC) compounds this cooling. These problems are worsening.

Members of the global wine industry have responded vigorously to the harmful effects of climate change and environmental degradation through global organizations such as the Porto Protocol Foundation, the Regenerative Viticulture Foundation, the International Wineries for Climate Action, and locally through the Dodon Center for Ecological Farming, which Polly and I established last year. We hope you will join us by becoming informed about the challenges of climate change, supporting these and many other climate-focused groups, talking with your neighbors about what you learn, and taking other practical steps. The wine industry may be among the first to experience the full effects of climate change, but it will not be the last.

2024 Vintage in Review

Happy New Year 2025!

Co-owners Tom Croghan & Polly Pittman

Just as we aim to farm in the service of nature, we seek to farm in the service of our community. In the spirit of reporting to our community “shareholders,” I offer this 2024 review. It’s lengthy, but there is much to report: a fantastic harvest, widespread recognition of our environmental approach, and the slow emergence of plans for our next chapter.

2024 Vintage in Review

Most vintages in the mid-Atlantic are a struggle, characterized by too much or too little rain, late frost, and excess humidity. The most recent season wasn’t one of them; we had a spectacular vintage.

After a very wet winter, the mostly dry season offered the calm, smooth rhythm we hope for (but never plan for). With plenty of chill hours, bud break began mid-April at 76-degree days, marking the first time since 2021 that vine phenology was in sync with the rest of the ecosystem. Over the next few weeks, temperatures dipped below freezing four times, but the wind machines limited frost damage to small areas of the West Vineyard. Nature hinted at authority, keeping us alert and thoughtful, but we avoided crushing blows.

Nearly perfect bloom weather meant an excellent fruit set. Record hot, dry weather during June and July limited disease pressure and sped the march toward ripening. Veraison appeared on July 15, the earliest ever. Two inches of rain over the next week refreshed the vines, the cover crops, and their human tenders to make a solid push to harvest.

Nighttime temperatures also dropped as low as the mid-40s, rising into the 70s in the afternoon during mid-August and early September. This diurnal variation is perfect for ripening, slowing sugar accumulation and evaporation while promoting flavor and phenolic development.

Sauvignon Blanc grapes on their way to the press.

We started picking the Sauvignon Blanc on the north slope of the East Vineyard on August 26 and quickly moved through the remaining Sauvignon and Chardonnay, finishing on August 30. The Sauvignon Blanc acids and flavors held up admirably despite the excessive heat of the summer, making this vintage our best ever. The Chardonnay was somewhat less resilient but still excellent. We wish we had more volume, but the vines are recovering from three years of significant frost damage from 2020 through 2022.

After a week-long break, we leisurely picked 2.5 tons of Cabernet Franc from the swale in the South Vineyard. We took this fruit directly to the press and fermented it in stainless steel to make an exceptional Reserve Rosé, one of our most sought-after wines.

The vendanges peaked on Thursday, September 12, when an early nor’easter started moving up the east coast from Florida. The team harvested 23 tons in an extraordinary effort, picking from dawn to dusk over six days. The last fruit arrived on the crush pad at noon on Tuesday, September 17, one hour before thirteen days of rain began. Kurtis and Katie then wrapped up the season with two weeks of 16-hour days in the cellar.

Cabernet Franc hanging on the vine.

Part of the harvest team after the last block of grapes was picked.

Overall, we harvested 39 tons of outstanding fruit. While about 12% less than the 2023 vintage record, the balance and quality could not have been better. In many ways, the 2024 vintage demonstrates that luck is the confluence of preparation and opportunity. The vines tolerated the drought because of the increasing soil organic matter, the transition to Guyot Poussard pruning, and a knowledgeable, committed team willing to put the mission before themselves.

With the satisfaction of having outrun the rains, the 2024 vintage offered a happy break from the usual chaos of the growing season, evoking Johannes Linstead's Between Tears. It allowed us to stretch our skills in new ways, fusing a decade and a half of growing and winemaking experience with the complexity and diversity of the natural world to create the signature harmony, balance, and depth we seek. The result is perfectly summarized in Emmanuel Pahud and Jacky Terrasson’s elegant Aprés un Rêve (after a dream).

Thumbs up to a great vintage.

New Threats and Old

While it was a lovely vintage, it still brought worry. Two new threats arrived at Dodon this year. Both can devastate a vineyard and are typically treated with intense insecticide applications. In each case, we’ve opted for a different path.

Spotted Lanternfly, or SLF, is an invasive planthopper that feeds on sap, robbing the plant of essential nutrients. While it can feed on many trees, its preferred hosts are the invasive Ailanthus trees, also known as Tree-of-Heaven, and grapevines. Adults are active in August and September during the harvest, swarming into some vineyards by the millions. In many cases, wine quality is compromised. Sadly, in some instances, SLF takes enough nutrients that the vines cannot survive winter dormancy. One colleague in Pennsylvania lost 35 acres of vines early in the SLF epidemic.

Recent research has shown that birds and other SLF predators leave them alone when they have fed on Ailanthus but eat SLF when they feed on different plant species. We have thus aggressively eliminated Ailanthus trees around the vineyard, hoping that natural predators will substantially reduce the SLF population size. When we found adult SLF almost exclusively on dead or dying Ailanthus in August, we left them in anticipation of cutting down those trees in December, thus allowing us to eliminate any SLF egg masses laid in the upper branches.

Discolored grape leaves can be a symptom of Pierce’s Disease.

We’re also taking a landscape approach to reduce the impact of another new arrival—Pierce’s Disease, or PD. PD is a bacterial infection caused by Xylella fastidiosa and spread by leafhoppers such as the broad-headed sharpshooter. Xylella and sharpshooters are commonly found in our region, but infection in grapevines has been controlled until recently by cold winters, which limited bacterial survival in the vines.

The conventional approach to treating established Xylella infections is vine removal and intensive insecticide applications during May and June when sharpshooters are active. But as my colleague Sam Droege of the U.S. Geological Survey’s Bee Lab reminds us, we can’t spray our way out of an endemic condition.

Just as with humans, the crucial step in controlling the consequences of any infection, in this case, Xylella, is to ensure healthy plants that are resilient to disease and the conditions that aggravate it. Xylella infects the xylem, the plant’s vascular structure that carries water and nutrients from the roots to other tissues. Plants with robust immune systems – for example, with plenty of phytonutrients like Vitamin C – living in healthy soil with aggregate structure to store water will tolerate infection. This is likely why we did not observe the typical signs of Pierce’s Disease until the extreme drought conditions of last summer, while many of our neighbors observed signs and symptoms much sooner.

As with Ailanthus, we are modifying the landscape outside the vineyard to reduce the spread of PD. Broad-headed sharpshooters prefer wetland habitats like the area that connects the South and East Vineyards. To make this area less hospitable to sharpshooters and Xylella, we’re removing invasive and dominant plant species, like mugwort, multiflora rose, and native grape vines, and replacing them with aromatic mints, such as bergamot, elderberry, and willow. The result will benefit the environment and the vineyard while also providing edible plants that we plan to use for non-alcoholic beverages, herbal teas, and medicinal purposes.

Spotted Lanternfly found on Ailanthus tree trunk.

I want to recognize the Maryland Department of Agriculture’s Spotted Lanternfly division and the team from the Integrative Ecology Lab at Temple University for helping to scout and develop an eco-friendly approach to what could be a damaging SLF infestation. We also thank Sam Droege and my colleagues Paulo Pereira and Emmanuel Bourguignon from the Living Vineyards project for their help envisioning the wetland restoration project.

For most sectors, environmental challenges loom on the horizon. But for wine growers, they are here. One example is the recent story of our colleague Stephen Cronk and his wife, Jeany. They sold their Information Technology business in London and moved to a Provence vineyard. Since purchasing the property west of St. Tropez in 2019, they've contended with severe frost and wildfires. (If you look through the charred timbers in the linked picture, you can see how close a 2021 fire came to their home.)

Stephen recently sent even more devastating news about their “nightmare” 2024 vintage, including frost, hail, rain during the harvest, flooding, and mudslides resulting from wildfire-induced vegetation loss in the hills that abut the vineyard. Stephen’s vintage summary for the Regenerative Viticulture Foundation, an organization he founded in response to concerns about his property's resilience, is included in RVF’s December newsletter.

In the Anthropocene, every region and every person faces new climate risks every year.

Other News

Hannah, Eleanor & Kurtis celebrate the end of a busy harvest season!

Babies and Such: On the human front, we were thrilled that, right after the summer bottling, Dodon team members Kurtis and Hannah welcomed their first child, daughter Eleanor. Kurtis was back by harvest, ready to lead the cellar work. Then, as we settled the last 2024 red wines into their barrels for the élevage, my son, Ian, and his wife, Michaela, welcomed their son, Kepler. Both babies are happy and healthy, bringing us additional joy. In between, Katie and JJ got married.

White House Initiative: In June, we joined the White House’s America the Beautiful Freshwater Challenge, becoming the first vineyard operation in the United States to do so. Led by Sara Gonzalez-Rothi, Senior Director for Water Quality (and a Dodon wine club member!), this partnership of 235 organizations seeks to preserve and restore freshwater ecosystems that provide us with food and water, protect our community from floods and storms, and offer a source of recreation and beauty. We are honored to be part of this extraordinary group of committed environmental leaders.

Wine Enthusiast Nomination: In September, Wine Enthusiast magazine announced that Dodon was among five nominees for its American Winery of the Year Award. As a relative newcomer, being included among legendary Napa Valley wineries like Schramsberg Vineyards is humbling. The winner, La Crema, is owned by the Jackson Family, founders of the International Wineries for Climate Action with Familia Torres. Jackson Family participates in the Porto Protocol’s Living Vineyards project, which I help lead. We salute the Jackson Family team and their work to ensure a better environment.

While our nomination was nominally related to our sustainability practices, as highlighted by Civil Eats, it truly reflects the team's commitment, dedication, and passion. Regina creates the collective effervescence that unifies a talented group to achieve shared goals that are collectively bigger than us. Katie’s critical thinking solves seemingly intractable challenges. Hannah’s grace, elegance, and wine knowledge make our service sparkle. Roberto’s persistence, enthusiasm, and devotion inspire all of us during summer’s dog days.

Promotion: Changes to the vineyard team have become a regular occurrence this time of year. I’m excited to announce that Kurtis will become Dodon’s winemaker in the new year. During his two years as Assistant Winemaker, Kurtis has demonstrated the initiative, determination, curiosity, and independence to take on this new role. He is also an extraordinary team player, eager to learn and contribute to all aspects of the business, including hospitality and financial management.

Couscous & Quinoa, Dodon’s KuneKune Vineyard pigs.

Pigs (yes, really): We’ve added Quinoa and Couscous, Kune Kune pigs from New Zealand, to the vineyard team. With weak neck muscles that prevent them from nibbling on leaves and fruit, Kune Kunes (pronounced Koonie Koonie, meaning “fat and round” in Māori) will graze the vineyard during the growing season to control weeds and add diversity to the soil microbiome, complementing the sheep droppings. Their short, upturned snouts also limit rooting and soil disturbance. And their gregarious disposition makes them great companions for the guard dog Willa, the ewes, and, of course, us humans!

New Evidence on Effectiveness of Agroecology: I have discussed our agroecological practices in a prior post, Farming in Service of Nature. At the time, these measures had solid experimental support, especially from the Jena Experiment, but their application in our vineyard was based mainly on intuition, listening to nature, and anecdotes. It’s reassuring that new research in real-life settings is validating our decisions. In a study in two Italian vineyards, researchers found that cover crop height is inversely proportional to fungal pathogen dispersal. A second study from Mendoza demonstrates the benefits of spontaneously growing grasses and forbs on carbon storage and biodiversity in row middles, albeit in a very different climate from Dodon’s.

Wine and Health:  My past work in mental health policy has followed me into the world of wine. I have stepped down after a decade as Chair of the Maryland Wineries Association Government Affairs Committee. This year, I was asked to join the WineAmerica Board of Directors to advise the organization on health issues. Alcohol, in general, and wine, in particular, have complicated effects on health. Assessing these effects with any precision is difficult. I enjoy working on these kinds of questions.

In December, a committee convened by the National Academy of Science, Engineering, and Medicine released its most recent evidence review, which Felicity Carter nicely summarized in the trade press. Sadly, mainstream journalism has rejected the conclusions of the world’s most objective, apolitical, authoritative scientific body. Continuing to report that alcohol consumption in any amount is detrimental to health ignores the possibility that wine with dinner likely poses little risk for most people, and it may bring benefits to our health, which, as the World Health Organization reminds us, goes beyond disease prevention to include one’s wellbeing.

The Next Chapter

The wine industry may be at the forefront of the climate catastrophe, but all agriculture is approaching the firing line. According to the United Nations Food and Agriculture Organization report “State of the World’s Biodiversity for Food and Agriculture,” agriculture’s current industrial model is destroying itself and us with it. The report details the alarming damage to the biodiversity that sustains crop production. It describes our reliance on an increasingly small group of species, the destruction of habitat and land-clearing, and the unsustainable use of resources. And this is just the consequence of biodiversity loss. Extreme weather, drought, rising temperatures, and degraded soil add to the challenge.

The magnitude of the challenges ahead of us is daunting. The possibility of the food system collapsing is increasing, yet our political leaders have failed to act. Experts proposed a national food policy a decade ago. In 2019, the Eat Lancet Commission created a “planetary health” diet to reduce greenhouse gas emissions and improve health. Still, we have yet to produce a national or state food policy or to incorporate climate change into our national dietary guidelines.

Without political leadership, businesses and individuals are trying to implement the necessary changes. Doing so will be more complex and challenging than it should be without public leadership. Only the government can coordinate and finance an effort of this size and ensure the benefits and costs are equitably distributed. But, as Paul Hawken writes in The Ecology of Commerce, “The promise of business is to increase the well-being of humankind through service, creative invention, and ethical action.” We must still do our part.

At the Vineyard, the “triple aim” approach I proposed two years ago has served us well as a roadmap. Over the past decade, we’ve used the planetary boundaries framework to enhance biodiversity, reduce eutrophication and pollution, and remove carbon dioxide from the environment. We’ve been transparent when reporting our successes and failures.

In this context, we have begun to plan new farming operations to create a sustainable food source. While still in the early phase of the new project, which I call the “Do Your Part Initiative,” here are five key components of the vision that Polly and I have developed:

• Converting the tree plantings to the north and east of the East Vineyard to a silvopasture that combines the benefits of trees and hedgerows with grazing.

• Adapting the current grazing areas to silvopasture by planting 350 apple trees will also allow cider production.

• Adding a “potager” or chef’s garden in the bowl between the winery and the South Vineyard will create what we hope will become a beautiful entrance to the winery that produces food.

• Developing a “food forest” garden west of the Sauvignon Blanc blocks (West Vineyard), including picnic areas for our Wine Club Members.

• Establishing a nonprofit “Learning Center” to provide apprenticeships for beginning farmers, bring together established fruit and vegetable producers to create new markets, and educate the public and policymakers about agroecology.

We would welcome your input as we continue to shape plans. We are most excited about crafting a vision of what a just, ecological society could look like. It’s doing our part.

As always, we are deeply grateful for your support. Happy New Year! 

The Vineyards at Dodon is now on iNaturalist App

Welcome to The Vineyards at Dodon Nature Restoration project.

Living, vibrant ecosystems are crucial to achieving our environmental, community, and winemaking goals. Over the past decade, we have implemented farming practices that encourage diverse native and naturalized plants in and around the vineyard while discouraging invasive plants that can easily dominate the landscape and provide habitat for detrimental insects.

Now, we need your help monitoring our progress. iNaturalist is an online network of people sharing information about biodiversity. By downloading the iNaturalist app and recording your observations when you visit, you will record the number of different plant, insect, and avian species and their relative frequency on the property.

You can find the iNaturalist app in your App Store. You can learn how to use the app here.

Please remember when making observations that Dodon is a working farm where safety precautions should always be observed. Your safety is our top priority, and we appreciate your understanding and cooperation in this matter.

• Always wear appropriate shoes and clothing when walking around the property.

• Watch carefully for uneven terrain, gopher holes, and other obstructions.

• Use sunscreen and insect repellent; check for ticks frequently.

• Keep an appropriate buffer between you and the livestock. Do not approach, try to pet, or feed Willa, Dodon’s livestock guardian dog, the sheep, or the chickens.

• Do not bring any dog near the sheep.

• Do not enter the vineyard or meadow unless you are accompanied by a member of the Dodon staff.

• Do not let your children explore the property unaccompanied.

• Do not pick any flowers, touch the grape vines, or taste grapes without explicit permission from a team member.

Have fun learning more about the natural world around us.

Farming in Service of Nature

written by: Tom Croghan, co-owner and winemaker

When we planned the first vineyard field trials in 2007, Polly and I aimed to produce high-quality wine with a light environmental footprint. And from the beginning, our viticulture received high marks for sustainability.

Sadly, our farming at the time was misguided. The landscape had been devastated by centuries of conventional agriculture. Our “sustainable” practices reduced the rate of harm, but they did not reverse it. Instead, we were unintentionally perpetuating a methodical march to environmental degradation.

Over the last decade, we have drawn from many sources outside of viticulture to learn methods consistent with our values, including the traditional methods of Cuban farmers who fed a nation following the collapse of the iron curtain, novel science that explains the inner workings of ancient ecosystems, and the inspiration of our colleagues at Future Harvest.

Rather than preserve the destructive cycles of our early years, our farming practices now focus on regenerating soil health, restoring biodiversity, and enriching ecosystem function. We aim to create a wholesome environment for the vines and those who work with them by reducing chemical, plastic, and nutrient pollution while enhancing biological activity.

Regenerating Soil Health

Healthy soil is a complex ecosystem composed of living organisms (microbes, invertebrates, and roots), organic matter (the remains of these once-living things), rocks, water, and air-filled pores. Winemakers like to talk about the unique minerals that produce all the fine qualities of the wine they make. But soil’s real value is in the living part and its detritus.

The Chesapeake Bay’s western shore soil in the 17th century likely contained about 5% organic matter. It was less than 0.3% by the time we first planted grapevines. The structure and composition of the soil had significantly shifted from its native configuration.

A few dominant bacterial species replaced the diverse microbes that maintain woodland ecosystems. None of the nematodes, arthropods, or earthworms crucial for nutrient cycling, soil structure, and fertility remained.

At Dodon, we rely heavily on the tools of agroecology to regenerate the soil. Our goal now is to accelerate, as much as possible, the natural soil-building processes that once dominated the region.

We start by limiting tillage to the area under the vines and cultivating diverse cover crops in and around the vineyard. After experimenting with non-native cover crops like mustard, radishes, and annual ryegrass, we’ve learned that spontaneously growing, perennial grasses and forbs adapted to the local environment are best.

Our recent surveys reveal up to thirty different species per square meter. This extraordinary plant diversity is associated with improved soil structure, diverse microbial populations, large below-ground invertebrate populations,  excellent water infiltration and storage, and high soil oxygen content.

Second, we apply organic amendments that add carbon and other essential nutrients to the soil. Using a foundation of ramial woodchips, we balance the compost with azolla. This rapidly growing aquatic plant scavenges the nutrients in the runoff from Dodon’s horse pastures. We also add the byproducts of our winemaking – spent yeast, stems, and skins. These practices both build soil and reduce the eutrophication that results in the Bay’s dead zones.

We incorporate indigenous microorganisms into the compost using soil from the surrounding forest. These bacteria, fungi, and archaea suppress disease by improving vine nutritional status, activating plant defense mechanisms, secreting antimicrobial substances, and increasing tolerance to injury. They also produce complex macromolecules, such as ascorbic acid, terpenes, and polyphenols, that defend the plants and make flavorful wine.

Finally, we integrate herbivorous grazing animals, or ruminants, into the system, supplying the new populations of microbial detritivores necessary for carbon, nitrogen, and phosphorus cycling. Our pasturing method, formally known as adaptive multi-paddock grazing but more commonly called “MOB” grazing, reproduces the evolutionary patterns of early grazers that may have allowed the earth to cool following the mid-Miocene climatic optimum.

Restoring Biodiversity

Loss of biodiversity may be humanity’s greatest threat, even more than climate change. Food production is the primary cause. At Dodon, we seek to reverse this trend and thus enhance the ecosystem services that will allow us to reduce our physical and chemical footprint.

Diverse vegetation in and around the vineyard – between the vine rows and in surrounding meadows, hedgerows, and woodlands – creates a habitat for mixed populations of vertebrate, invertebrate, and microbial life. Beneficial insects, in turn, reduce pest populations, enhance soil structure, and support microbiomes. In addition, highly diverse agricultural systems result in better yield, less pest damage and pesticide use, more carbon sequestration, and higher nutrient density.

Enhancing insect diversity may also benefit grape yield and wine flavor considerably. For example, Nicole Sierra-Rolet, also a member of The Porto Protocol, reports a 30% increase in yield at Chêne Bleu in southeastern France, which she attributes to larger bee populations.

Another colleague, Nuno Gaspar de Oliveira of Natural Business Intelligence, has demonstrated the transfer of native yeasts by butterflies from the surrounding landscape onto the developing grapes during vine bloom. These yeasts can later be found in the fermentations, contributing to the complexity of wine flavor.

To achieve these goals, we encourage native, low-growing grasses and forbs between vine rows by crimping tall grasses that out-compete other desirable species. In addition to their benefits on soil health, terminating these cover crops at bloom releases nutrients from decomposing roots and adds a mulch layer that cools the soil and prevents the spread of soil-borne fungal pathogens. 

Pollinator meadows, hedgerows, and other natural areas offer beneficial insects and wildlife food, shelter, and places to breed and raise their young. In 2018, we installed three acres of meadows with 28 native grass and forb species, including Rudbeckia, Asclepias, Solidago, and Heliopsis spp., contributing to ecosystem benefits and season-long beauty. Remarkably, vineyard blocks adjacent to the meadows no longer require treatment for Japanese beetles, a significant insect pest in our region.

To extend these benefits, we contracted with the Maryland Department of Natural Resources to plant 1600 trees and shrubs as hedgerows this spring. Several species, such as Corylus americana (American hazelnut), Prunus angustifolia (Chickasaw plum), and Castanea pumila (dwarf chestnut), were once essential food sources for the first peoples of our region. 

Enhancing Ecosystem Function

During the first meeting of Maryland’s Healthy Soils Advisory Committee, one of the members, an experienced and highly regarded farmer, was surprised to learn that he might have a soil health problem. He had become so accustomed to using fertilizer, pesticides, cultivation, and irrigation that it hadn’t occurred to him that a fully functioning soil ecosystem might reduce or eliminate the need for these inputs.

While we often think of agricultural landscapes solely in terms of food production, they are multifunctional. Farm ecosystems provide a habitat for microbes, insects, and birds that suppress diseases and pests, purify water, and store carbon. In addition, they offer opportunities for recreation and aesthetic beauty. In other words, farm landscapes play an essential role in our well-being.

Restoring these ecosystem functions is not straightforward, however. Returning to the past is neither possible nor desirable. Humans arrived in our region about 8-10,000 years ago when a much colder climate sustained the nomadic hunter-gatherer population. The area remained woodland until European settlers brought plows, smallpox, and novel plants and animals, changing the landscape forever. The pre-European ecosystems would support neither modern human needs nor a vineyard of wine grapes.

Neither will the current agricultural system that is dependent on chemical, plastic, and carbon pollution. So, what to do? We are in uncharted territory without a clear roadmap. Rather than following a prescribed recipe, we observe nature for lessons. How are similar invasive species managed in natural settings? Why have carbon dioxide levels declined in other epochs? How do animals graze in the wild, and what are the consequences?

We believe we are on the right path in choosing the holistic process evoked by Orgel’s Second Rule, “Evolution is cleverer than you are.” It’s a deliberate route, dependent on trial and error at the generational timescales of microbes, insects, plants, soil, humans, and geology. It considers the well-being of people and the organisms with which we share the planet.

Given these constraints, the process is remarkably swift. And it appears less prone to unanticipated consequences than quick technical fixes, the latest trend, or magical thinking.

When planting, we tend to focus on native species of plants that support native insects. Defining native, however, is complex. Take narrow-leaf plantain, for example. This naturalized “weed” is native to Great Britain. Unlike more invasive species like Johnsongrass and multiflora rose, it has integrated well, providing diversity, nutrients for butterflies and bunnies, and medicine for people without overwhelming the landscape.

Most people consider narrow-leaf plantain a native, recalling hours of shooting the seed heads during childhood. Immigrants – plants, insects, and people - can add wonderfully to our lives, a lesson in reciprocity we would do well to understand.

We planted the oldest vineyard blocks in the east vineyard fourteen years ago. From the beginning, we confined tillage to the area under the vines, eliminated herbicides, and planted several species of tall fescue as a cover crop. Following the difficult 2018 vintage, we intensified the effort by adding multispecies cover crops, initiating the compost program, and integrating sheep.

As a result of our effort, we’ve observed better soil structure and water infiltration during increasingly frequent extreme rain events. Soil organic matter has increased 10-fold, representing about 2500 tons of sequestered carbon dioxide. We reduced insecticide use by 70% and fungicide use by a third. Meanwhile, increased plant phytochemical levels, such as ascorbic acid, produced resistance to pest pressure and better wine.

Looking Forward

While our early results are promising, the long-term is not assured. Globally, the challenges associated with greenhouse gas emissions, loss of biodiversity, chemical and plastic pollution, and eutrophication are compounding. Our methods may help us temporarily adapt to a changing climate. Still, they will only reverse the underlying trend if applied broadly and combined with dramatic changes in how we produce energy and use land.

The most recent report from the Intergovernmental Panel on Climate Change makes clear that the climate crisis has resulted in crop failures, food shortages, and hunger, even as conventional solutions worsen the problem. The report calls for the radical transformation of agriculture using the agroecological tools we employ at Dodon.

The lesson of the Dodon story is that while these methods often deviate from established practice, they are feasible and seem to help. We’ve learned to discard an either/or mentality to find values-driven, integrated solutions that benefit the environment, the community, and the company. It tells us to farm with intention, purpose, and gratitude. Our obligation, and our privilege, is to tell this story.

2019 Vintage Summary: Tranquility and Transformation

Things may have seemed simple in 2019, but they were not.

After the rains of 2018, the 2019 vintage brought welcomed change. Unusually dry weather that started in mid-July helped make the harvest, at first blush, delightfully simple. The vines politely stopped growing at veraison, focusing their energy on ripening the fruit. The vineyard team was, well, in the vineyard, the work progressing quickly and efficiently. Picking, sorting, and processing seemed almost effortless. The wines made themselves.

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Club events were equally agreeable. The dry ground meant we could use the new parking area without preparing for towing duty. Dodon ‘til Dusk wasn’t canceled for rain, and Alley and her mostly new service team did a remarkable job learning their roles, revising procedures to enhance the DtD experience, and making all of us feel at home.

But underlying the triumphs were hidden challenges. The 2018 growing season - with its heavy precipitation, saturated soil, early defoliation, and poor nutrient storage - had lingering effects. In 2019, canes, buds, and the vineyard floor still contained high levels of residual fungal pathogens. Average low temperatures were higher than normal, limiting the number of “chill hours” (the number of hours the vines are exposed to temperatures between 32 degrees and 45 degrees F) that are required to break dormancy. The consequences were bud failure, excessive shatter (when the new seeds are not fertilized), and isolated bunch rot in the period before harvest, despite the near-perfect weather.

Still, the vintage proved exceptional. Although yields were low, about 20% less than usual, the quality of the harvested fruit was outstanding. The wines are continuing their annual trend toward greater depth and complexity, consistent with the increasing age of the vines. These characteristics were enhanced by long maceration times, allowing us to extract the full range of flavors. The Sauvignon Blanc and Rosé will soon be bottled; we are thrilled with them.

Lessons Going Forward

For the past year and a half, we’ve focused on understanding why 2018 was so damaging and on how we can be better prepared for the future. Our path to greater resilience involves two courses of action. First, we need to become more flexible in our harvest and winemaking strategies, such as when to pick early and make Rosé, when to alter our usual extraction processes, and what to do when we get caught with less than perfect fruit.  We now have written protocols with criteria for their use for each of these situations.

We are also making fundamental changes to our vineyard practices. Because of my background in medicine and immunology, as I read more about the underlying science, the central concepts have emerged with clarity. While our farming has always been at the forefront of sustainability, 2019 is the year we hastened the pace of Dodon’s ecological approach to farming.

Throughout the vintage, we invested heavily in a set of practices that focus on improving soil, enhancing biodiversity and ecosystem services, and enriching the health, vitality, and resilience of the plants. Many of the techniques that we’ve adopted are the natural extension of our past effort to mimic natural processes, but our new focus centers primarily on soil and soil biology.

Soil with structural integrity, a diverse microbiome, and high levels of organic matter carries out many vital functions. It provides essential support for plants, protects against both drought and flood, removes environmental toxins, and improves water quality. Particularly important in today’s world, soil stores large quantities of carbon – more than twice the amount found in the atmosphere. Putting more carbon in soil will play a crucial role in addressing the underlying cause of climate change.

Healthy soil is the result of the biological interaction between plants and microbes. Just like the microvilli of the human intestine, roots are the mechanism that plants use to take in nutrients. As in humans, a balanced diet is essential for plant health. The best diets come from rich topsoil with good nutrient and water holding capacity, characteristics that allow the plants to produce complex phytochemicals that improve their structural integrity and strength, promote disease resistance, and enhance flavor.

Microbes – protozoa, fungus, bacteria, and archea – play several crucial roles in healthy soil. First, they decompose organic matter and secrete organic acids that breakdown rocks, releasing nitrogen, phosphorous, sulfur, and other nutrients that can be absorbed by plants, and they enhance water regulation by producing glycoproteins that improve soil aggregates.

Roberto and Tom construct a Johnson-Su bioreactor, a type of static, aerobic composter.

Second, beneficial microbes compete with pathogens for nutrients, secrete antimicrobial compounds and lytic enzymes that inhibit pathogen growth, and boost plant systemic host defense by stimulating production of phytochemicals. The result is an environment known as disease-suppressive soil that protects plants from pathogens.

The devil, of course, is in the details. There isn’t a textbook on ecological vineyard systems that translates these concepts into methods to create healthy soil, and only a few peers in the industry have taken this approach. The closest techniques are those used in biodynamics, but the supporting science for this very specific set of practices isn’t yet well-developed. As a result, we looked instead to other agricultural, natural, and scientific systems – everything from forestry to paleopedology (the study of soils from past geological eras) – and to our own property, where native grape vines live and thrive in the woods, not the pastures.

Turnips have a deep taproot that breaks up compaction.

Reasoning that grape vines would likely be healthiest in a forest-like setting supported by nutrients and microbes that are common in that ecosystem, we decided to emphasize growth of diverse fungal species that prefer woody food sources. Our compost program now emphasizes wood chips, and we’ve constructed a static, aerobic composter inoculated with soil from the woods just outside the vineyard. We hope that this compost will contain native mycorrhizal fungus species that will interact with the vines to produces better soil, healthier plants, and better fruit.

Because different plants provide diverse nutrients to soil microbes, we’re also working to enhance plant diversity within the vineyard. One method is to use highly heterogeneous cover crops. Our mix this year included eleven different species of grasses and forbs. A custom-made roller crimper has helped as well. When perennial grasses are mowed, hormonal signals stimulate regrowth. In contrast, crimping tall grasses terminates their growth and allows other plant species to flourish. Crimping also provides a mulch layer, cooling the soil to provide a better environment for fungal growth.

Crimping enhances plant diversity and cools soil.

Will these methods work? The conventional wisdom that vines need to struggle to produce the best wine gives pause to many of our colleagues, but it does not convince me. It’s true that overly vigorous vines with abundant foliage produce wines that lack structure and taste “green” from too many methoxypyrazines. The question is whether this vigor is produced by healthy soil with high levels of organic matter, or whether it is more likely to occur in unhealthy soil exposed to excess mineral nitrogen and phosphorous from fertilization, tillage, or excess rain.

Recent research from Germany suggests that vines raised in healthy, microbially active soils have smaller shoots, lower pruning weights, and fewer leaf layers, all signs of reduced vigor, as compared to conventionally grown grapevines. Perhaps in this context, “struggling” refers to the appearance of small, contained vines focused on reproduction and not vines struggling to feed a depleted microbiome by producing excess foliage.

Our practices are supported by research published over the past decade in scientific journals like Cell, Science, and Nature. They are based on cutting edge research and represent a significant departure from standard viticulture. After 30 years away from the lab, it’s fun to again read journals that formed the foundation of my scientific career.

But the reality is that the methods we are adopting are not new at all. Nature had a pretty good system before Thomas Jefferson invented the moldboard plow, Robert Koch developed germ theory, and Norman Borlaug initiated the green revolution. While these innovations resulted in robust increases in food production and saved billions of lives, they are also associated with degraded soil, reductions in nutrient density, and increasing input intensity. By looking to the past, new science that reintegrates ecology into the toolbox may move agriculture into a safer, more resilient, and healthful future.

We do not yet know which specific practices will be the most effective in the vineyard, but it would be folly to keep doing the same things as in the past. We are heartened by the support of our wine club members and a few leaders of the wine industry. It is indeed both exciting and daunting to be redirecting our growing strategies, and we welcome your feedback.

The final story of 2019 vintage is thus a tale of two vintages. The first – simple, unchallenging, straightforward – reminds me of an Ignaz Pleyel flute concerto, extraordinarily popular during Pleyel’s lifetime but which have become obscure with time. The second vintage - more scientifically and intellectually demanding - is reminiscent of Mozart’s Flute Concerto No. 1 in G major. Composed shortly after he had been dismissed from the Viennese court, this concerto represents the rebellious defiance of defeat that eventually thrust Mozart to the pinnacle of classical music.

The challenges of the 2018 vintage proved to us that simply sustaining the status quo would not be enough to withstand the consequences of the rising temperatures and extreme weather events that scientists predict for the future. Rather, we are convinced that restoring a functional ecosystem represents the best path forward in terms of wine quality, as well as environmental stewardship. Stay tuned as 2020 unfolds, and we learn more.

Climate Change, Part 2: A New Year’s Resolution

As a farmer and grape grower, the effects of climate change are hard to miss, and the news is getting worse.  Even the best-case projections regarding temperature, sea level rise, floods, fire, disease, and agricultural output are frightening. Partly due to changes in the climate, extinction rates among all species are about 1,000 times greater than they would be in the absence of human activity. Pulitzer prize winning author Elizabeth Kolbert has called this phenomenon The Sixth Extinction.

Ecologists and philosophers have started to wonder whether humans will survive the climate change experience, reminding me of a Tom Lehrer tune from the 1960s. Expecting that we will survive, my Christmas wish is that the resulting world will be the kind in which our grandchildren will still want to live.

The immediate cause of changes in the climate is an imbalance between carbon storage in soil and other reservoirs and its release into the atmosphere as carbon dioxide, trapping heat and acidifying the oceans. (You can learn more about the carbon cycle here.) While burning fossil fuels gets most of the attention, modern agriculture, through deforestation, mechanical and chemical disruption of soil, and confined livestock facilities, has contributed as much as 40% of the increase in atmospheric CO2.

It doesn’t have to be this way. Trees, grasses, and other plants carry out photosynthesis that uses the carbon from CO2 to produce sugars that are transported via the roots into the soil, feeding a diverse ecosystem of microbes, insects, earthworms, and even vertebrates.  Agricultural approaches may thus be deceptively simple yet practical and potentially powerful methods to extract CO2 from air and store it as organic carbon in the soil. Research suggests that adding 0.4% more organic matter each year to agricultural land across the globe would sequester all the CO2 released by human activity.

Is 0.4% per year additional organic matter achievable? Absolutely. Using cover crops and advanced grazing techniques, North Dakota rancher and farmer Gabe Brown has added organic matter at about twice this rate for 25 years, providing proof of principle. University of California at Berkeley Professor Claire Kremen has done the design work, USDA’s Sustainable Agriculture Research and Education program has done field trials and created educational programs and tools, and organizations such as Future Harvest CASA and county agricultural extension offices offer support, education, and knowledge sharing among farmers and landowners in our region.

Put simply, while building soil organic matter may be only one part of an overall solution to global warming, it is literally “shovel ready.” The challenge now is spreading the word, creating the incentives, and putting on our boots. As we approach the start of the 2019 session of the General Assembly, there are several critical actions to take.

First, we should hold Governor Hogan and the Maryland Department of Agriculture accountable. In 2017, the General Assembly passed the Maryland Healthy Soils Act that requires MDA to provide incentives that would improve soil health, monitor progress, and help the state meet goals set by the Maryland Climate Change Commission. Despite the promise, no new practices or incentives have emerged. To reinvigorate this program and regain climate leadership for the state’s largest industry, Maryland could join California in committing to the Global Soil Health Challenge.

Second, state and county representatives should add a “carbon note” to all legislation. Proposed legislation in Maryland is always accompanied by a “fiscal note,” a brief description of the potential financial consequences of the bill. But fiscal notes don’t include other indirect costs to the taxpayers, such as the cost of global warming. In order to help legislators understand the benefits and risks of legislation on climate change, a similar “carbon note” could be required. The practice would help keep the issue front and center.

Third, we need to modify incentives so that farmers will implement methods that will add carbon to soil.  Today’s agricultural methods were developed during the Green Revolution, in the aftermath of the great depression, the dust bowl, and World War II, when energy was cheap and plentiful and people around the world were hungry. Tax policy, agricultural programs, and business practices designed to support these systems now have entrenched interests behind them, making alternatives hard to implement. Difficult as it may be, revising tax policy to account for the climate-related costs of carbon use would accelerate the transition to “carbon farming.”

There are also a few things you can do at home to return carbon to the soil. First, you can let your grass grow. As it grows, the ratio of carbon to nitrogen in the blade increases. In contrast, short cuttings (those that result from weekly lawn mowing) have high levels of nitrogen that, because there is little carbon to hold it, then leaches into ground water and the Bay. Infrequent mowing, annually is best, has other advantages. Less fuel and labor are needed, long roots improve soil structure allowing better water infiltration, and over time a natural meadow of diverse plants, insects, and wildlife will develop.

Second, you can plant an edible landscape on even a small plot of ground. Americans often plant vegetable gardens during times of scarce resources. About 20 million households established victory gardens during World War II, and nearly half of all Americans grew their own vegetables during the early 1980s recession. The personal benefits include reductions in transportation (both from farm to market and market to home), better nutrition, and the sense of community that comes when everyone does their part.  There are added benefits of incorporating these herbs and vegetables into the landscape in terms of soil health, reductions in pesticide use, and aesthetics.  

Because they sequester twice as much carbon as forestland, vineyards represent an excellent way to add carbon to soil. When we started, average soil carbon was less than 1%, and unmeasurable in some areas. Through cover cropping, reduced soil disturbance, and compost additions, we are up to about 2.5%, about the norm for most vineyards in the world, but we think we should go higher.  Although conventional wisdom says that vines should struggle, we believe that additional organic matter will result in healthier, more resilient plants that will resist disease, ripen earlier, and have more flavor. At least this is the experience of some of the best châteaux on the left bank in Bordeaux.

While storing carbon in soil is a simple tool to help solve the current climate challenge, the transition will not be easy. Agriculture is more perspiration than romance, and some of these methods are labor intensive. Farm labor is in short supply, and there will inevitably be a process of trial and error as we determine the right crops and cover crops for our environment and each agricultural product. In the short term, these factors could result in reductions in farm incomes. But long term, reducing CO2 and creating resilient landscapes is the best way to prevent, or at least mitigate, the catastrophes of climate change.And, of course, more carbon in the soil leads to more nutritious, flavorful food and wine, and that will also make our grandchildren’s world a better place to live.

Climate Change, Part 1: A Christmas Wish

Polly and I are spending the holidays with our granddaughter, Juana Magdalena, in a little town called City Bell, just east of Buenos Aires. Polly’s three daughters are all here too, almost as much fun as Juana. As the summer solstice passes, our days are filled with family, exercise, asados, newspapers, a bit of sightseeing, and, for me, Spanish lessons. There is a fruit and vegetable farm within walking distance, and freshly butchered meat and chickens on the way, with none of the planting, weeding, feeding, watering, and picking chores of farm life.  

The family time also allows us to reflect on this new grandparenting stage of life. We intensely appreciate the diverse beauty and richness of the world as we experience the munificence of family, friends, and colleagues. Building on the knowledge of a hundred thousand years of evolution and the gifts of our parents and grandparents, we can learn and debate, try to understand the universe and our place in it, and create beauty through art, literature, music, and winemaking. As at the farm, I awaken each morning profoundly grateful for these gifts.

And yet, I wonder, as all grandparents must, what kind of a world Juana will inherit.

The world has changed a great deal in my lifetime, mostly for the better. In his recent book, Enlightenment Now, Steven Pinker has documented the extraordinary progress we humans have made to improve health, safety, family incomes, and life expectancy; expand democracy, education, and equal rights; and reduce poverty, hunger, and violence.

This progress extends to many environmental challenges, especially those that are visible to the naked eye. The Chesapeake Bay is (slowly) getting cleaner, acid rain has declined, and bald eagles have returned.  Deforestation of the Amazon has slowed, the amount of protected terrestrial and marine habitat has increased, tankers spill less oil, and the ozone hole is getting smaller. This progress, Pinker argues, is the result of activism, legislation, regulation, technological innovation, and global cooperation, and it leads Pinker to be optimistic about the future.

Yet there are enormous challenges ahead. For most of the past 420,000 years, atmospheric carbon dioxide levels remained below 300 parts per million (ppm). They started climbing during the industrial revolution, reached 315 ppm when I was born and now exceed 400 ppm. The average temperature in Anne Arundel County has climbed from 55.4 degrees F to 56.9 degrees in my lifetime. Multiple reports, including those from the Fourth National Climate Assessment and United Nations Intergovernmental Panel on Climate Change describe the expected rise in temperature and sea level, destructive storms and fires, increases in mosquito and tick-borne diseases, and declining agricultural output. Our experience during the 2018 vintage is perhaps an ominous preview.

But these challenges, as significant (and devastating) as they might be, don’t reflect all the vitality and beauty of the ecosystem in which we live and the danger it faces from climate change. In Yellowstone Park, native plant species are being replaced by invasive cheatgrass, reducing forage for wildlife. On the Galapagos Islands, increasingly frequent El Niño conditions block the flow of nutrients that feed plankton, threatening penguins, marine iguanas, and even Darwin’s finches. The number of insects has declined, at least in some parts of world, by more than 75% because of habitat loss and intensive use of pesticides.

The rapid loss of plant and animal species is frightening. For example, what would happen if there were no pollinators? It turns out that life without them can endure, but it may not flourish. After overuse of pesticides eliminated bee populations decades ago, growers in the Maoxian Valley of Himalayan China hand-pollinate hundreds of thousands of apple and pear trees. Because fewer pollen-donor trees are required and humans effectively pollinate 100% of the flowers (bees only pollinate about 30%), yield per acre increases. Because they don’t need to worry about killing beneficial insects, these growers can use more insecticides to produce the unblemished fruit that brings high prices.

If efficiency, defined by higher yields and prices per unit of input, is the goal, then hand-pollination is the way to go when human labor is cheap and plentiful. Moreover, the image of an entire village turning out every spring to pollinate the region’s crop, each person brushing the flowers on 10-12 trees each day, conveys a certain sense of nobility and identity. Despite these advantages, this world seems sterile, lacking complexity, balance, depth, interest, and resilience, and our experience growing wine suggests it does not result in the best fruit. Likewise, most apple producing areas of the Himalayan region have chosen to reestablish pollinator populations and have not followed the path taken in the Maoxian Valley.

As humans, we cultivate our own welfare, and hopefully produce the best wine, by enhancing the health, diversity, and abundance of life around us, and not by disrupting ecosystems, destroying large sections of habitat, or raising animals in confinement, methods that might have more immediate financial return but don’t reflect their true economic costs. My Christmas wish is that Juana will find the beauty and strength that comes from being part of an interconnected whole, sheltered and nourished by nature, and that she will use her compassion, ingenuity, and knowledge to enrich the ensemble of the soil, water, air, plants, animals, and people that surround us.

2018 Vintage Summary

Tuesday, October 2 was a beautiful, if somewhat warm, autumn day – the kind of day that we hope for in early October, when we are typically just starting to pick the black grapes. But this, the final day of picking in 2018, signaled the perplexing character of the vintage. The image of Dodon’s weather vanes pointing toward each other on an otherwise lovely morning is its lasting symbol.

The year started with brutally cold temperatures, as low as two degrees below zero (Fahrenheit) on the morning of January 7. While a few weeks of very cold temperatures has many benefits in the vineyard, we start to worry about bud viability when temperatures approach zero. In contrast, February was usually warm – speeding vine phenology - but March was cool – slowing the vines. Bud break occurred in the Chardonnay on April 15, about on-schedule, followed by freezing temperatures three days later.

The next variety to bud, the Cabernet Franc, waited until May, indicating that a late year would ensue. Yet this isn’t what happened. Bloom, which typically occurs 45-60 days after bud break, arrived just 24 days later. Suddenly, it was an early year, requiring adjustments to already modified schedules for canopy management and sprays. The vines were confused by the temperature extremes, as were their human partners. Dodon’s vineyard manager, Roberto Gomez, finally thawed from winter pruning, complained of vertigo.

And then it rained. And rained. And rained. The soil at Dodon is made up of about 50% solid matter – rocks, minerals, microbes, insects – and 50% pores, occupied by air and water. When the pores fill completely with water early in the season, the roots don’t have enough oxygen to develop normally. In response, the leaves produce more stomata (the structures responsible for evapotranspiration) than they would otherwise. The effect is to make the vines more susceptible to drought.

So of course, drought came in early July, and the vines became stressed. As we finished irrigating the south slope, it started raining again, this time lots of it. Our colleague Jim Law of Linden Vineyards described it as biblical in its proportions. We had more rain in September than in the previous five Septembers combined. And when it wasn’t raining, it was hot and very humid. Most people correctly associate excess moisture, whether from humidity or rain, with molds and mildews. But by drowning the roots late in the season, excess rain causes the vines to focus on survival by growing roots and foliage, diverting energy from ripening.

Our usual response to excess rain is to let the canopy grow higher, increasing evapotranspiration, and let the grass grow to create competition with the vines. But this year the amount of rainfall overwhelmed these measures. The canopy developed downy mildew, and the grass grew so quickly that we couldn’t keep it out of the fruit zone. The fruit ripened unevenly, with the ripest fruit falling prey to botrytis and other late season bunch rots. We sorted heavily while picking, leaving about half of the black fruit on the vineyard floor.

To say that the vintage was, and remains, puzzling is an understatement. We never quite knew what to expect. The vines remained confused all year, with growing shoot tips appearing around the vineyard throughout September. This atypical behavior also occurred in other plants, particularly crab apples and magnolias that could be seen blooming throughout southern Maryland this fall.

Decisions about picking were particularly uncertain. In mid-August, I told the team that I didn’t think we would begin picking for at least two weeks. Four days later, we picked the first of the Sauvignon Blanc followed by the Chardonnay, both from the east vineyard. We waited a week to pick the Sauvignon from the west vineyard.

We also picked the black fruit earlier, and thus less ripe, than in the past. In the cellar, we extracted less aggressively, leaving behind the unripe tannins that cause bitterness. With less structure, the wines will need less oak and more stirring to achieve their potential. As a result, the 2018 red wines promise to be more accessible early in their life, and less age-worthy, than is typical for Dodon wines.

Despite the challenges, or maybe because of them, I’m left feeling extraordinarily grateful for this vintage and the lessons that it brought. There were many bright spots. Our effort to create a balanced ecosystem seems to be working. The increasing diversity of insect life around the vineyard is stunning, and except for the occasional spot treatment, we didn’t use any insecticides this year. A mantid even joined us on the sorting table this year.

While there was a bit of mold in the Sauvignon clusters, the white wines turned out beautifully. I’m especially excited about the Chardonnay, which has the depth, range, and vitality that we seek from this classic variety.

The main lesson, though, is that the climate is changing rapidly. Over the last three years, old weather patterns have given way to prolonged periods of drought and rainfall. It has tested our farming and winemaking skills, the front of house team who rearranged plans daily, and even club members who had hoped to attend one of the seven rained-out Dodon ‘til Dusk gatherings. (Thank you for your patience.) These challenges will continue, especially in the mid-Atlantic where temperatures and rainfall are predicted to rise faster than in other parts of the world.

In response to these changes, we need to think critically about how we can adapt and become more resilient. It’s crazy to irrigate in a year of record setting rainfall, but that’s what we needed to do. Fortunately there are solutions, some that we are already working on. Soil with good structure allows excess water to pass through quickly to the aquafers below. Soil rich in organic matter holds on to some of the water until it is needed by the plants. In the pastures, we can create this healthy soil using a technique called MOB grazing; in the vineyard, we can create it using appropriate cover crops with deep roots and plenty of residual biomass.

As the year comes to an end, the 2018 vintage reminds me of Bach’s six suites for solo cello, performed wonderfully by Yo-Yo Ma.  Each suite is based on a different French dance, and each is composed of six movements that span the range human emotion, none the same but all very beautiful. The same might be said of the variation that occurs between vintages, and in 2018, variation within the vintage. Like Bach’s cello suites, some vintages are deep and soulful, some sad and mournful, others light and lively, but all with their own exquisite charm. The lesson of this vintage is that we can succeed by dancing together as a community to nature’s varied tunes.

Looking Beyond Organic Agriculture: Part II, Biodynamic Agriculture

In my last post on organic agriculture, I discussed the importance of balance in the vineyard, especially in the soil where microbes play a critical role in creating a healthy environment for plant growth. This notion of ecological balance is central to a form of organic agriculture known as biodynamics. 

First proposed by German philosopher Rudolf Steiner during a series of five lectures in the 1920s, practitioners of biodynamic agriculture view the farm itself as a self-contained ecosystem that requires balance to function properly. In other words, in optimal circumstances, a farm can function successfully without external inputs. 

Biodynamic agriculture is practiced throughout the world in many agricultural systems, including vineyards, and it has long had a certifying organization (Demeter). Many of Burgundy’s most well-known wineries, such as Domaine Leflaive and Domaine Leroy, rely exclusively on these techniques in their vineyards. The practice is also common in Bordeaux (for example, Château Palmer), the Loire (Château de la Roche aux Moines), and Sonoma (Bonterra Organic Vineyards and Benziger Family Wines). 

Those who practice biodynamics believe that their fruit is healthier and ripens earlier, and that the resulting wines have more depth and balance than those grown using conventional or standard organic techniques. These winemakers also believe that biodynamic wines are more reflective of the terroir in which they are grown.

Several biodynamic producers tie shoots together and form an arc, tucking the growing end back down into the trellis. Despite the lack of sunshine and absence of hedging or leafing, I didn’t see any mildew, and the wines made from these vines are clearly the product of fully ripe grapes. Something is clearly in balance.

There are many parallels between organic and biodynamic methods, including composting, cover cropping and companion planting, integration of livestock and crops, and avoidance of synthetic pesticides.  Indeed, organic certification is a requirement for Demeter’s biodynamic certification. What distinguishes biodynamic from organic agriculture is a set of practices that Steiner believed would harness non-physical “life-forces” that influence biology in desirable ways. 

These “dynamic” practices consist of planting, cultivating, and pruning according to phases of the moon, and use of nine “preparations” that include homeopathic doses of specific organic (cow manure seasoned in horns), herbal (for example, tea made from stinging nettles), and mineral (silica) substances that are applied as either soil amendments or foliar sprays.

I’ve been intrigued by biodynamics since we started the vineyard ten years ago. Ideas related to balance and healthy, living soils are consistent with our views at Dodon regarding the best ways to make wine and improve the environment. To explore biodynamic methods in more detail, Polly and I met last summer with biodynamic practitioners in both Burgundy and Bordeaux. 

We found that, while many vineyards actively promote the philosophy and tools of biodynamics to improve the quality of wine while reducing environmental impact, there is in practice a very broad range of interpretation and application of these precepts. Indeed, at the practitioner level, the definition of biodynamics is very hard to pin down.

Most of those with whom we spoke endorse applications of the preparations in the hopes of reducing use of synthetic pesticides and fertilizers. For the most part, however, these producers have not identified specific improvements in fruit or wine quality, nor have they noted reductions in their need for organic or synthetic pesticides since they started integrating biodynamic practices. In a difficult vintage, these producers are willing to use non-biodynamic tools as needed.

Eric de Suremain of Château de Monthelie picking stinging nettle used to prepare biodynamic preparation 504. The nettles are buried in wooden boxes or clay pots encased in peat for 1 year and then added to compost. Stinging nettle is said to have a relationship with iron, helps stabilize nitrogen, and promotes formation of humus.

For a small number of producers, however, such as Jean-Michel Comme, technical director at Château Pontet-Canet, and Eric de Suremain, fourth generation owner of Chȃteau de Monthelie and Domaine Eric de Suremain, biodynamics is a way of life. Jean-Michel and Eric have taken extraordinary risks to avoid use of non-organically certified material to maintain balance in their vineyards. Their stories are both interesting and informative. 

Jean-Michel and Eric view every aspect of life – the vineyard, the wines, the people, and the broader landscape – in terms of their relationship to nature and balance among the four essential elements of life – earth, air, water, and fire. Their biodynamic practices attempt to integrate these elements to regenerate the land. 

Weather, animals, vine varieties, invasive plants, insects and microbial pests, and human activity can all shift this elemental balance from health to disease. Rather than treating disease directly, however, the strategy is to return balance and harmony to the vineyard by feeding the soil. For example, Cabernet Sauvignon, a “fire” variety, usually does not do well in wet areas of a vineyard. In this case, fire and water are in conflict. Jean-Michel, however, has been able to balance these properties to produce stunning Cabernet from low lying areas of his vineyard where water often is in excess.  

In the vineyard with Jean-Michel Comme at Château Pontet-Canet. The dip in the background is an area that I would have predicted would have too much water for good Cabernet Sauvignon, but through Jean-Michel’s careful management of weeds and preparations, the fruit is always very high quality.

How does he do it? Jean-Michel scouts his vineyard daily for weeds that are associated with excess water. When found, he might use equisetum (a foliar spray) and silica (a soil amendment).  Both are elements with fire-like properties that make up two of the biodynamic preparations. Doing so results in more balanced growth, and the vines are much stronger and have a higher disease resistance. 

Jean-Michel also looks for the underlying causes of imbalance and lasting methods to restore it. When he identifies certain plants, bacteria, or animals in the vineyard, he doesn’t necessarily try to change them. Instead he views them as nature’s response to imbalance. In order to form an environment that is both complete and unique, he farms in a way that encourages synergy among the vines and their surroundings. In doing so, he creates a farm with individuality and distinction that ultimately translates into the special wines of Pontet-Canet. 

Despite the intuitive appeal of biodynamic agricultural methods, strict adherence comes with considerable risk. During the difficult 2016 vintage in Burgundy, Eric lost more than 90% of his crop, producing just 14 barrels from 40 acres, despite spraying for mildew 28 times, about twice his norm. This level of pesticide, even one that is organic, is likely to intensify imbalance, not reduce it. 

And then there is the fundamentally mystical interpretative framework of biodynamics. Despite their natural sources and homeopathic doses, the biodynamic preparations are still chemicals. While they could restore balance in some situations, they could also reduce it if misapplied. We also don’t know with any degree of certainty the benefits of carrying out vineyard tasks according to the phase of the moon, despite the obviously strong gravitational force that it exerts on the earth. 

What does all this mean for Dodon? The basic tenets of biodynamic agriculture are very similar to the agroecological methods that we’ve adopted. Both are focused on the relationship of the farm with nature, using biological principles to create balanced, diverse ecosystems characterized by healthy, microbially active soils, beneficial insect populations, and efficient long-term storage of carbon to create productive crop systems. For Dodon, the lessons of Jean-Michel and Eric are to listen carefully to what nature is telling us, and to think critically about our relationship with our surroundings. 

A new plot of wildflowers, including astor, buckwheat, coreopsis, dill, and several clovers, in Dodon's experimental vineyard. While the diversity of insect activity was stunning, these crops were too tall to plant under the vines, did not hold up to tractor use, and attracted deer that quickly turned their attention to eating the ripening fruit.

The challenges to creating a balanced ecosystem at Dodon are extraordinary. The property was farmed for nearly a quarter millennium with tobacco, followed by a half century of conventional tillage, synthetic fertilizers and herbicides, and limited crop rotation. Much of the surrounding landscape, farmed in a similar manner, has now transitioned to suburban turf grasses that require synthetic fertilizers and pesticides. All of this most certainly destabilized any natural balance that might have existed prior to the original patent to Frances Stockett in 1658.

It will take time, patience, creativity, intellectual honesty, and perspiration to restore Dodon to a balanced ecosystem. In future posts, I’ll discuss some of the ways, starting with rebuilding the microbial life of the soil, that we are trying to integrate with the surrounding ecosystem and what we’re learning from these experiments
 

What are Dodon Soils?

When Polly and I were in Bordeaux a few years ago, we visited Damien Bielle, technical director at Château La Gaffelière. La Gaffelière is a Premier Grand Cru Classé estate that lies on the descending slope below St. Émilion’s famed limestone plateau. It’s adjacent to Château Ausone, one of only four class A château in the most recent St. Émilion classification. La Gaffelière is one of 14 Premier Grand Cru Classé B château.

As we looked up the hill, Damien explained how the special soil of the plateau and the hillside location had produced many of the region’s great wines. When we turned to return to the cellar, we could see Château Pavie, also Class A, to the southeast at the base of the slope where the soil becomes more alluvial and sandy, where one might think the soils would be less likely to produce the stunning wines of the plateau. When we asked Damien how Pavie achieved its status despite the presumed challenges of its site, Damien’s response was matter of fact and utilitarian. “They know how to farm it,” he said. 

It turns out that the four St. Émilion class A chateau – Ausone, Angelus, Cheval Blanc, and Pavie –each have very different soils from one another, and even within their vineyards, there is considerable variation. The key is that the wine growers at each site intimately understand their soils, and they adapt their viticultural and winemaking methods accordingly. 

How are soils classified?

Because soils across the world differ, the United Nations Food and Agricultural Organization has created a comprehensive taxonomy that characterizes soils based on their characteristics and suitability for agriculture. There are six taxonomical levels. The highest, most general level is the soil order; the most specific is the series. There are 12 orders and more than 15,000 series. With so many series, the characteristics of the soils within each are very similar. 

There is no dominant soil order among the world’s wine growing regions, let alone specific series that are associated with the best wines. This fact alone leads to the conclusion that high quality wine grapes can be grown on different types of soils. Inceptisols are the most common soil order in Bordeaux, alfisols in Burgundy and the Loire, and mollisols in northern Italy, California, Oregon, and Washington, and the ancient wine regions of Armenia. Alfisols, which are good for many agricultural uses, are also found in Maryland and Virginia west of the fall line.  

Dodon’s soils substantially differ from those in other wine growing regions. Termed Marr-Dodon complex soils, they are described as fine-loamy (meaning smallish particle size), siliceous (rich in silica that warms the soil), semiactive (modest cation exchange associated with low fertility), mesic (medium temperature), aquic (Dodon series) or typic (Marr series) (aquic soils retain more water than typic) hapludults (derived from sandstone). 

Hapludults belong to the ultisols, an order found in humid climates and characterized by high degrees of weathering, mineral leaching, and acidity. They age very rapidly, leading to rapid turnover in rock and mineral content. With relatively low fertility, they are marginal agricultural soils that require significant inputs for most crops, but these characteristics make them good candidates for viticulture.  Ultisols have a well-developed reddish clay horizon (horizons are the distinctive layers that can be seen at various depths below the surface) associated with weathered sandstones and resulting in their common name “red clays” in the southeastern United States.

Dodon’s distinctive soils represent a considerable opportunity to make wine that will differ from those produced in other regions, even when the climate and grape variety are the same. The process of discovering what the final wines will be like adds enormously to the excitement and pleasure of our project. I often wonder whether Dodon Merlots will exhibit the power found in Pavie, the finesse in Cheval Blanc, the minerality in Angelus, some combination, or none of these. While we have some early hints, each vintage brings new learning. What we do know is that understanding the nuances of the vineyard soils and farming them with care and precision are essential to the process of discovery.

How do we study soil?

We started by understanding what we mean by soil, which usually depends on whom we are talking with. Engineers, concerned chiefly with the stability of buildings, roads, and other structures, define soil broadly as any material that can excavated without systematic drilling or blasting. In other words, to an engineer, soil is everything above bedrock, which is about 3,000 feet below the surface at Dodon. 

Soil scientists and farmers take a narrower view of soil, defining it as a medium that can support rooted plants. Soils that meet this definition vary in depth, mineral and rock composition, and hydrology. Since most agricultural plants are relatively shallow rooted, only surface soils have been surveyed by the United States Department of Agriculture. Dodon series soils have been characterized to a depth of 72 inches. Because grape vines can send roots more than 200 feet below the surface, they are influenced by soils well below typical agricultural assessments.

Even though soils within a series (Dodon series, for example), have very similar characteristics, there can be, and usually is, significant variation on any given parcel. At Dodon, geologist Bubba Beasley documented this variation using electromagnetic induction imaging to identify plots that differ according to water holding capacity, mineral content, and texture. The resulting image represents a rich mosaic of individual plots, each created hundreds of millions of years ago and transported to Maryland’s western shore uplands. (I’ll describe the origins of Dodon’s soil in a subsequent post.)  

Uploaded by The Vineyards at Dodon on 2014-09-05.

How do we use our understanding?

We used the information from the survey to lay out the vineyard in ways that would maximize our chances of creating complex, balanced wine. For example, Merlot grown on clay soils tends to have more structure and intensity than those grown on sandy soils, where the wines are often described as elegant and finessed. Because we think of Merlot as foundational for Dodon wines, most of our Merlot is planted on plots with more clay where we hope it will have good intensity and structure. 

The information from our survey allows us to precisely farm each plot. For example, areas of the vineyard dominated by sand and gravel have less water holding capacity than areas with more clay. We are a bit quicker to irrigate those parts of vineyard. Because of the leaching, we include calcium and magnesium in our nutrient management program, providing small amounts of these essential elements to thicken grape skins and provide both more flavor and better disease resistance. 

Bubba found that some parts of the vineyard were nearly “dead,” with compacted grey soil that lacked microbial and insect life, undoubtedly the result of fifty years of “conventional” agriculture characterized by excessive use of herbicide and inorganic fertilizers, and by compaction associated with use of heavy equipment. The wines from these areas of the vineyard are weak, lacking the structure and fatness that we want for Dungannon and Oronoco. To restore life to these plots, we’ve been using deep tillage, adding compost and compost teas, and strategically planting deep rooted cover crops to create better soil structure and allow oxygen to enter the soil. 

It’s all, of course, a bit of an experiment, with educated guesses dominating our hypotheses. Because the soils differ from those in other parts of the wine growing world, we can’t merely duplicate their methods. And even after hundreds, or even thousands, of years, the Bordelais are still learning. A winemaker from Pomerol recently told us that he had been working for 43 years to improve one plot of Cabernet Franc that consistently ripened a week or two after the others in his vineyard. His last experiment involved adding river gravel to the soil. Even though he added only a small amount, the result was higher sugar levels but also green notes in the final wine, making him worse off than he had been. If the Bordelais don’t have all the answers for their plots after thousands of years of experience, we can’t really know after just ten how to optimize the wine from any given plot at Dodon. And so we've started on a long and interesting journey of discovery and learning. 
 

Why do we care so much about Dodon soils?

Grapevines grow just fine in water supplemented with a few nutrients, a method known as hydroponics. Growing hydroponically has lots of advantages. Because it can be done indoors, hydroponics allows perfect temperature control, and it avoids disease pressure often associated with rain, humidity, and insects. Vegetative growth can easily be regulated by adjusting the amount of carbon dioxide in the atmosphere and the amount of nitrogen in the aqueous solution. It’s little wonder that tomatoes, lettuce and other vegetables, and most commercial marijuana are grown hydroponically.

But many wine growers stubbornly cling to ancient notions of terroir, the idea that the place in which the fruit is grown has a major influence on the taste of the final product. These “terroirists” view themselves as interpreters of their vineyards and not as creators of a wine. They view wines that express the characteristics of the vineyard, such as the minerality often seen in cool climates with limestone derived soils, as ambassadors of “place,” and by association, the vineyard, the farm, and the surrounding community.

There are several ways in which soil can affect the way that wine tastes. The first, and probably the most important, is the movement, distribution, and purity of water in the soil. The amount of water available to plants is determined by the soil’s slope, texture, rock and organic matter content, and depth. Vines in areas with too much water available to them tend to grow vigorously, using energy to produce more foliage than is optimal to ripen the fruit. Indeed, wine grapes tend to do best in conditions of modest water deficit during ripening, and it’s this characteristic that has resulted in the aphorism that vines must “struggle” to produce the best wine.

Soil mineral content plays a substantial role in shaping the characteristics of wine. Minerals in soil largely come from weathering rocks, but they have a much more ancient origin, forming just a few million years after the Big Bang. Most of the earth’s 4,500 known minerals are composed of combinations of just six elements – oxygen, silica, aluminum, calcium, magnesium, and iron. For the most part, the effects of minerals on wine are indirect. For example, in wet conditions, orthoclase feldspar (composed of silica, oxygen, and potassium) is converted to kaolinite clay, releasing potassium that is taken up by vines and transported to the berries. During fermentation, high levels of potassium can precipitate tartrates and reduce acid levels, giving wine a flat, flabby taste. On the other hand, high levels of dolomite (an oxide of calcium and magnesium) compete with potassium uptake, thus increasing wine acids, and it is associated with thick skins, resulting in resistance to infection and more intense flavor in the wine.

Finally, living organisms in soil directly and indirectly influence the characteristics of wine. Microbes – bacteria, yeasts, fungi – provide nutrients in digestible forms to the vines, and they compete with plant pathogens. They digest dead plants and animals to form organic matter that acts as a store for nutrients and water. Many microbes make their way into the fermentation tanks, altering fermentation kinetics and the flavors that result. Larger organisms, such as insects and worms, modify soil structure, allowing better drainage and oxygenation that promote vine health and ripe fruit. Together with the other components of soil, living organisms help to form a dynamic, complex ecosystem that is constantly changing and renewing itself.

Those of you who have toured with us know the effort that we’ve made to understand Dodon’s soil and its origins, the care we’ve taken to select the most appropriate varieties and rootstocks, and the attention we’ve paid to laying out the vineyard to best match the plants with the underlying soil. Despite the potential of hydroponics to make consistently good wine, we’ve chosen the more difficult, potentially more costly traditional methods because we believe that soil plays an essential role in crafting wines of depth, harmony, and balance that reflect the place in which they were grown. In subsequent posts, I’ll describe the story of Dodon soils, where they come from, what they are, and how they make Dodon wines.

Looking Beyond Organic Certification: Part I

I’m often asked when leading guests on a tour in the vineyard whether Dodon is “organic,” or at least aspires to be certified as an organic vineyard. It’s a fair question. In many ways, we fit the common image of organic farmers. On a summer visit, you will find our vineyard team out with hoes, clippers, and other hand tools, carefully cultivating the soil and tending the vines. Regulations governing organic certification require practices that are standard operating procedures at Dodon, such as use of organic composts, mechanical weeding, and use of biological controls for insect pests. These methods are labor intensive and expensive, and they illustrate our commitment to sustainability, ecologically-friendly practices, and a balanced ecosystem.

But the answer to the question is no. Dodon is not, and does not aspire to be, certified as an organic vineyard.

Despite the pastoral image of the organic farmer, the main difference between organically certified and conventional agriculture is the use of synthetic pesticides. Organic certification standards allow use of non-synthetic, and a few synthetic, chemicals, while conventional agriculture does not have any restrictions regarding use of synthetic compounds. Because non-synthetic substances are derived from biological (e.g., Bacillus thuringiensis toxin), botanical (e.g., neem and pyrethrins), or other sources (e.g., minerals such as sulfur and copper), they are considered more “natural.”

But non-synthetic chemicals are still chemicals, and they are often toxic to non-target organisms, including people. Take pyrethrins, a group of six naturally occurring substances derived from Chrysanthemums. These plant extracts have been used as insecticides for millennia, and depending on the specific extraction methods, many are certified for organic use. Pyrethrins are highly effective against a broad range of insect pests. Unfortunately, they are also highly toxic to beneficial insects, such as honey bees and other pollinators, much more so than many synthetic insecticides that target a narrower range of insects.

Because the real differences between conventional and organically-certified agriculture are small, some of the most ecologically-minded farmers have chosen to forego certification. They believe that meeting certification requirements is a diversion from the real objective to produce healthy food in a sustainable manner and may be detrimental to the crop and the environment. When Polly and I were in California last summer, we visited one such farmer, Bob Cannard, at Green String Farm whose produce is served at Chez Panisse, Alice Waters’ well known Berkeley restaurant. Bob is widely known for his visionary, yet radically unconventional, approach to growing fruits and vegetables.

Bob Cannard with students at Green String Institute. If you look closely you will see the vegetables (our half) among the diverse cover crops (nature’s half).

Bob believes that healthy, tasty, nutritionally complete plants are the result of a large and diverse population of microorganisms in the soil. These microbes fix nitrogen, digest carbon containing organic matter, secrete acids that break down rocks into minerals, and protect roots from invading pests. Creating this diversity requires that we renew the soil with a complex diet of composts, shells, rocks, and decomposing plant material from diverse forbs that also provide habitat for beneficial insects. Bob summarizes it with the phrase, “Half for you, half for nature.” Failure to feed nature its portion leads to imbalanced and depleted soil, unhealthy plants, and inferior food.

None of this diversity and balance is required for organic certification. Most of the organic produce in your local grocery store comes from farms that may meet certification requirements, but they are just as sterile as conventional farms. These farms are home to single crops treated with (organic) chemicals such as sulfur and copper that reduce microbiological life in the soils. In the extreme, some organically certified produce is now grown indoors in water supplemented with nutrients, no soil or biodiversity required.

Cabernet Franc vines after the 2014 harvest in Dodon’s experimental vineyard. The vines on the left, treated using standard pesticides as recommended by the extension service, defoliated following infection with Downy Mildew. The organically treated vines on the right held their leaves much longer, but note the telltale blue tint of the copper.

Our trials at Dodon, done in partnership with Virginia Tech plant pathologist Mizuho Nita, convinced me that while we could successfully produce high quality fruit in most years using methods that would allow organic certification, the environmental costs would exceed those associated with a more ecologically-based program that includes judicious use of synthetic pesticides. For example, while copper adequately protected the vines from fungal pests, it required very high doses that would in the long run poison the soil and reduce microbial life. And a combination of pyrethrins and pepper spray reduced Japanese beetle pressure, but we had to apply it three times a week, reducing beneficial insect levels and creating more problems.

None of this discussion should be taken as criticism of the organic farming movement. By and large, it’s a big step in the right direction. But because the methods required for certification did not advance our environmental or winemaking goals, we’ve chosen to look beyond organic agriculture to a more ecologically friendly approach. In future posts, I’ll talk about what we are doing to create a sustainable, balanced ecosystem that is rich in diverse bacterial, insect, and plant species. We hope that these new techniques will result in healthier vines, earlier ripening, and better wine, all with fewer chemicals, organic or otherwise.

One Winegrower's Take on GMOs

Support for genetically modified organisms or GMOs got quite a boost this summer when the National Academy of Sciences released their most recent report on GMOs, concluding that, compared to “conventionally” farmed crops, GMOs have had generally, but not uniformly, positive effects on producer income and that they are safe to eat. To be sure, the NAS committee comprehensively reviewed the literature comparing GMOs with conventionally farmed crops, so from this perspective, it fulfilled its narrow statement of task. But many winegrowers will view the scope of the report as limited, comparing two largely technologically driven agricultural methods but leaving out more ecologically-based methods that rely on diversified ecosystems to improve quality and increase yields.

What we now call conventional farming has its origins in the Green Revolution, an effort led by Nobel laureate Norman Borlaug to increase crop yields, defined as the number of calories produced per acre of agriculture. Relying on high yield, disease resistant varieties, mechanization, and inorganic fertilizers, the then new agriculture virtually eliminated famine in India, China, and Latin America in the years following World War II. But these techniques also came with challenges. The focus on a few varieties reduced genetic variation and thus increased susceptibility to some diseases. Widespread use of pesticides resulted in increasing resistance to them among the very insects and weeds they were intended to treat, and overuse of fertilizers has polluted ground and other waterways, including the Chesapeake Bay.

GMO technology is largely intended to solve the problems associated with now conventional farming while continuing the search for increasing yield. After a quarter century of experience with crops modified to resist insect pests and herbicides, which represent the majority of commercially available GMOs, some progress is being made. Bt maize is a type of corn modified to secrete a natural bacterial toxin effective against corn borer caterpillars. Use of Bt maize has been shown to increase yields by about 9%, and because it is associated with reduced use of alternative, broader spectrum pesticides, its use also appears to be associated with increased diversity of beneficial insects in farm fields. The benefits of herbicide (usually glyphosate) resistant crops are less apparent. Yields have not increased in most cases, and because the gene has “drifted,” many weeds are now also resistant to this once useful product. And our colleagues Claude and Lydia Bourguignon have shown that use of these herbicides has reduced microbiological activity in soil by as much as 85%, reducing both quality and pest resistance among food crops.

In contrast to the genetic techniques that produce GMO crops, agroecological methods (the approach that we take at Dodon) blend respect for traditional farming with modern tools. For example, creating a diverse agricultural ecosystem that provides habitat for beneficial insects appears to reduce dependence on chemical insecticides. According to Miguel Altieri, Professor of Environmental Science, Policy, and Management at the University of California in Berkeley, these methods have increased yields by 30-50% when compared with conventional methods, much better than the 9% increase seen in studies of GMOs. Altieri has also documented similar benefits using agroecological techniques at Benziger Family Vineyards in Sonoma.

At Dodon, we’re very concerned about some of the unintended consequences of GMOs that were not considered in the NAS report. As weeds have become resistant to glyphosate, several seed companies have created crops that are also resistant to broadleaf, growth regulator herbicides such as 2,4-D, dicamba, and triclopyr. Drift of these herbicides, sometimes over many miles, is common, and they are highly toxic to grapevines. Indeed, we have already seen what we think is triclopyr injury in some of our younger Chardonnay blocks. The source of the triclopyr isn’t clear; it could be a neighboring farm using it in a no-till system, a lawn care company, or a tree company clearing road or power line rights-of-way. What is clear is that widespread adoption of herbicide resistant crops will only increase use of these products on farms, and hence the associated risk to our vines. It’s an issue that keeps me awake at night.

Healthy Chardonnay leaves are shown on the left; on the right note the curled edges and differences in color and lobulation that could be the result of triclopyr exposure.

The focus on yield and a few other traits, such as shelf life, has resulted in striking loss of genetic variation in food crops. Before the Green Revolution, about 30,000 varieties of rice were cultivated around the world. Currently just ten varieties make up the vast majority of rice production. GMO crops are likely to reduce this further. Yet there is a price to pay. Think about the taste of tomatoes at chain grocery stores compared to those you get at the local farmers’ market. Food, like wine, is an ambassador of its community, reflecting the tastes, values, and traditions of the people who live there. When we lose the unique qualities of our local food, we lose something of ourselves.

This is not to say that GMOs are intrinsically bad. They are powerful tools that should be used in appropriate circumstances. Similar genetic methods are being studied to treat cancer, hemophilia, cystic fibrosis, and many other diseases. In agriculture, the Golden Rice Project is a global effort to use genetically modified rice to reduce Vitamin A Deficiency, a global public health problem that causes 500,000 cases of blindness and 2 million deaths in the developing world each year. It is this opportunity that recently caused more than a hundred Nobel laureates to endorse the project. If GMOs can help solve a problem of this magnitude, then by all means consider them. But do so in the context of all the alternatives.

A long time ago, another Nobel laureate, Arno Penzias, told me that the measure of a scientist is the quality of the questions she asks, not the quality of the answers she provides, advice that has served as a guiding principle in many parts of my life. The NAS understands this principle very well, and in response it has designed processes to ensure that its committees ask the most salient questions to examine from all perspectives scientific issues of national and global importance. Above all else, this comprehensive, balanced approach is the reason that the nation’s leading scientists give freely of their time to serve on NAS committees.

But in the case of its GMO report, the NAS seems focused on whether or not to accept GMOs, a dichotomy that I would expect from the manufacturers of GMO seeds and the environmentalists who seek to ban them, but not from an authoritative source like the NAS. It would be better to ask who, what, when, where, and how GMOs should be used. When and in what contexts do they offer the best alternative to the problem to be solved? What criteria should be used to make decisions about their use, and who should make those decisions? How do they stack up against alternatives? As Dr. Penzias admonished, the most important thing is to ask the right questions.

Are Time and Terroir an Illusion? Reflections on Mark Matthews’ new book, Terroir and Other Myths of Winegrowing.

Issac Newton described time in absolute terms that I find intuitive. It is the same everywhere, it has constant duration, and it flows continuously in the same direction. According to Craig Callender, Professor of Philosophy at University of California, San Diego, Newtonian time is a kind of master clock that carves our world into instants.

Over the past century, however, physicists have slowly chipped away at Newtonian time, so that most are now prepared to accept a timeless universe. Atomic clocks placed at the foot and summit of Mt. Washington do not give the same time 24 hours later. Experimental evidence from quantum mechanics has demonstrated that the future can influence the past. A single event is perceived as occurring at different times depending on the velocity at which an observer is moving. Stripped of these core features, is time nothing more than an illusion?

Claude & Lydia Bourguignon examine Dodon's soils.

While physicists debate the existence of time, agricultural scientists have long argued about the existence of terroir, a term that describes site specific influences on how we perceive wine. The most recent attack comes from University of California Davis professor, Mark Matthews, in his recent book Terroir and Other Myths of Winegrowing. Professor Matthews offers a comprehensive synthesis of research on the interaction between soil and grapevines, and finds little to support the notion that soils or other features of terroir contribute any unique qualities to the wines grown in them. In a way, it’s comforting to hear, again, that fine wine can be grown on many different soils. Winegrowers in a new region like the mid-Atlantic will find it good to hear there are no innate barriers to greatness.

Still, while a terroirless world may be easier to accept than a timeless world, both contradict millennia of recorded human experience. We can all agree that a Cabernet Sauvignon from the Medoc and one from Napa Valley taste different. Likewise, Sauvignon Blanc from the eastern Loire and New Zealand taste different. There are, of course, many factors that could explain these differences, such climate and weather, and vineyard and winemaking practices. That said, even within our own vineyards at Dodon, the taste of Merlot grown on the clay/gravel soils of Block 21 differs from the taste of the same clone grown on the sandy loam of Block 28, despite similar treatment of both in the vineyard and the cellar. It seems logical to conclude that something about the soil – its composition, structure, aspect, drainage and water retention properties, and microbial flora – has had an influence on the way in which the wine tastes.

The challenge with Professor Matthews’ thesis is that he attempts to answer the big question about terroir without clearly defining the outcome. To be fair, we don’t know a great deal about what to look for, but there are some common themes. Wines grown on chalk or limestone soils, as in Chablis for example, tend to exhibit a sensory characteristic known as minerality. If minerality is caused by this soil characteristic, then we would expect to find it in wines grown on similar soils. This is exactly what we find at Dodon in those parts of the vineyard planted on soils with layers of weathering oyster shells that share mineral characteristics with limestone. There are other wine characteristics that also seem to correlate with soil properties. Wines grown on clay tend to have a sticky quality on the palate; likewise, those grown in loam can have a powdery feeling.

Instead of looking at these sensory attributes, however, researchers have assessed far cruder outcome measures related to fertility, plant growth, and ripeness. As Matthews points out, grapevines grow well even when raised in a soilless environment, but this doesn’t mean that wines grown in diverse soils all taste the same. Although plant and fruit characteristics are not the outcomes of interest when asking about terroir, even using these crude measures, the studies seem consistent with an effect of soil properties on wine. Water restriction, whether through deficit irrigation or natural drainage, results in more color. Nitrogen availability is loosely associated with yeast metabolism and production of aromatic molecules during fermentation.

There are other flaws in Matthews’ arguments against terroir, some of which are simply unrelated to the core question he sets out to answer. For example, he points out that for most of the recorded history of winegrowing, terroir and its related tastes – goût de terroir if you will – had a pejorative connotation. Terroir wines were considered of lower quality, perhaps because of poor sanitation in the cellar that led to infection with brettanomyces, a yeast that gives wine a barnyard-like aroma. This historical view is interesting, but it is irrelevant to any rigorous understanding of the effects of terroir on wine. The same might also be said for his argument that terroir is nothing more than the invention of Burgundian marketing departments. And some of the arguments seem pointless. Although wines grown in various places can be distinguished by their mineral content, it would be silly to believe that flavor molecules are transported directly from the soil to the wine, so why spend the reader’s time rebutting them.

The idea that both time and terroir are illusions rests on the absence of evidence that they really exist. In both cases, human experience tells us otherwise. We perceive that time flows from past to future, serves as a useful measure of things like the duration of events and speed of a car, and allows us to get to appointments as scheduled. Our palates tell us that wines differ when grown in different places. The purpose of science is to explain our observations, so I’m confident that the scientists will eventually find the reasons for the discrepancy between their current research findings and our holistic experience. No fanciful belief in astral powers is required. In the meantime, the mysteries of both time and terroir are intellectually intriguing and fun to debate, so I plan to keep my watch handy and not miss tasting time.

Dancing with Nature

We are often asked in the depth of winter about the effect of cold temperatures on the vines. Usually, the answer is that cold weather during winter dormancy is good for them. Chardonnay and Merlot are the least cold hearty varieties at Dodon, and even these tolerate temperatures as low as -3 degrees F before there is any bud loss.

It’s a much different case in the spring, however. As the vines begin to emerge from dormancy, they are much less tolerant of the cold. The picture, taken this morning, shows a second leaf Chardonnay vine with buds in various stages of growth. Near the bottom, the buds are barely swollen and still very dormant. Buds at this stage will tolerate temperatures in the single digits. Moving up the vine, the buds are progressively swollen, near to the point of bud “break.” About half of buds at this stage will die when the temperatures reach 27 degrees F. Once the leaves have started to separate, they become progressively more susceptible to cold injury, as is the case with the bud at the top of the vine.

The vines at Dodon emerged from dormancy especially early this year after an unusually warm March. The temperature in the vineyard at 6am Wednesday morning was 23.2 degrees F, clearly well into the danger zone. We had prepared for the predicted cold by mowing the grass very short to capture as much warmth in the soil as possible, by cultivating the non-bearing blocks with small vines, and by spraying a mixture of potassium, calcium, and seaweed that alters the physiology of the vine in ways that mimic their dormant state.

Despite the extreme cold, the vineyard seems to be in good shape so far. We lost about half of the buds that had broken, but these are largely confined to the second leaf blocks of Chardonnay, where during our winter pruning, we left more buds that are needed for the coming vintage. Buds on the nearing vines appear healthy. More cold is on the way, with low temperatures in the high 20’s predicted, so we will spray again today. If an inversion is forecast (where warmer air is above a layer of very cold air at the surface), we will build fires at the bottom of each block to facilitate air circulation.