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.
