We are happy to share this guest blog by Igor Sill, vintner and winemaker, who shares the practices he uses to build soil health, reduce greenhouse gas emissions and foster biodiversity on Atlas Peak Mountain in Napa County.

We are now well into summer on our mountain vineyards, experiencing that magical time of the growing season when ripening Cabernet Sauvignon and Merlot grapes (called berries at this stage) begin to turn their colors, from green to reddish-purple. This stage of berry pigment development is called “veraison”.  The sunlight and warm temperatures cast their vital physiological functions and each berry’s sugars start to accumulate, softening the berries and changing their colors. The remainder of summer is all about ripening our Cabernet Sauvignon and Merlot grapes to perfection!

I chose to grow grapes in Napa’s high-elevation Atlas Peak volcanic appellation because it offers longer sun exposure and cooler nights, presenting a unique area for truly great wines.  What I didn’t realize was the many beneficial environmental aspects of Atlas Peak until 2 or 3 years of my ownership had passed. With the rising awareness about the environment, adopting eco-friendly farming practices geared to protecting our water sources, storing carbon, reducing greenhouse gas emissions, and maintaining soil health became a priority.  Over these last years, I’ve embraced my responsibility to preserve our soil’s health for our generation and the many generations to come.

As Franklin Delano Roosevelt once noted, “The nation that destroys its soil, destroys itself.”

We all agree that we must dramatically cut our carbon dioxide emissions to help limit global warming and avoid future climate catastrophes. The interesting thing is that cutting carbon emissions and redirecting carbon into the soil actually benefits the quality, health, and production of wine.

The purity of fresh mountain rain explains why some high-elevation vineyards become award-winning year after year.  Most Atlas Peak vineyards are dry farmed due to their volcanic soil’s ability to retain fresh rainwater and maintain soil moisture for months.  Thus, we don’t irrigate much, relying on the purity of direct rainfall to nurture vines for much of the growing season.  Amazingly, these very same volcanic rocks serve another equally important function, much like a sponge, they capture carbon dioxide.

We need many approaches to reduce gas emissions and remove carbon dioxide from the atmosphere. The Intergovernmental Panel on Climate Change report on mitigating climate change contains many such techniques and innovative approaches. Carbon dioxide removal, essentially pulling carbon dioxide from the atmosphere, is essential to combating climate change, according to the world’s leading scientists.  In farming vineyards, there are many responsible practices for removing carbon dioxide and preventing it from returning to the atmosphere.  We deploy many of these so as to help us reach our own climate goals. 

“After 15 years of doing research related to sustainable agriculture and soil ecology, it is exciting to witness the momentum that is building, especially in the wine industry, to mitigate climate change and build soil health. Given the large acreage of vineyards in California, I believe the industry can positively contribute toward the state’s climate mitigation and adaptation targets and serve as a prototype for other commodities” stated Charlotte Decock, Ph.D. Assistant Professor of Soil Health & Fertility, California Polytechnic State University San Luis Obispo.

In a natural process called “weathering”, our volcanic basalt rock terrain naturally absorbs carbon dioxide from the atmosphere.  We’ve added additional exposed volcanic basalt rock to this natural weathering process. This is accomplished by relocating large amounts of stacked rocks where they surround our vineyards and absorb carbon dioxide.

The 2017 Atlas Peak fires, and several more recent Napa and Sonoma fires confirmed our need for reforestation so as to keep carbon absorbed and stored.  Post fires we planted new oak trees and carbon sequestering coyote shrubs on the property so as to restore the capture of carbon dioxide. Turns out that while our vines, trees, and shrubs capture carbon dioxide as they grow, they also provide a natural fuel source in a process called “bioenergy generation,” absorbing and holding carbon for a longer time.  Our vines use sunlight, carbon dioxide from the atmosphere, and water for photosynthesis to produce oxygen and carbohydrates that our vineyard needs for energy, nutrients, and growth.

It all starts with the burning of biomass, such as vine cuttings left over from pruning, to produce biochar, a charcoal-like substance that stores carbon. Biochar is raked into the soil to keep carbon out of the atmosphere for long periods and improves our soil’s health and sustainability.  A recent Columbia Climate School scientific report highlighted both positive and negative impacts of climate change on plant growth. By proactively building soil health, we are preparing our vineyards for changing climatic conditions, so that we can minimize negative impacts and capitalize on a potential CO2 fertilization effect. 

We practice no-till farming which slows the rate of soil carbon loss and increases soil carbon levels.  Building our soil’s organic matter, along with cover crops replenishing the soil nutrients, provides us with nature’s fertilizer and healthier vines along with long-term carbon storage without impacting biodiversity.  As a result of these environmentally best practices, we’ve completed Napa’s Climate Adaptation Certification requirements.

I take the time to really listen to Mother Nature as she whispers her secrets so as to maintain an environmentally sound habitat around our vineyard.  We practice integrated pest management by welcoming falcons, owls, and hawks, added trees and shrubs as natural habitats that help to naturally control pests. These practices translate to greater biodiversity of a more sustainable ecosystem and our commitment to preserving our soil’s health for the many generations to come.  It all starts in the vineyard.

Learn more about Sill Family Vineyard here.