April is a time of growth – when plants move from dormancy to bloom and the Napa Valley’s landscapes are lush and green, with the rivers and streams full from early spring rains. During April, we also celebrate Down to Earth month, making it a great time to think about soil health and how to manage property using “Carbon Farming.”
Grapevines are essentially a carbon neutral crop (not accounting for tractor passes and tillage, fertigation, transporting the grapes, etc.). They store carbon during the growing season and release this carbon during harvest and over the winter, only to rebuild stores the next year. But there are many added decisions growers can make to increase the carbon sequestration on the farm and in the soil that can increase soil and vineyard health and productivity, increasing the overall resilience of the farm. That’s where Carbon Farming comes in.
Silenus Winery is one of the first Napa Green properties working with the Resource Conservation District (RCD) and Natural Resource Conservation Service (NRCS) to develop a custom Carbon Farm Plan (CFP) for their ~7 acres of estate vineyards. This will include a riparian replanting project that will involve voluntarily removing 0.35 acres of low-performing vineyard along Dry Creek and replacing that with a native riparian buffer of trees, plants and grasses to prevent the spread of Pierce’s Disease, thus creating an 85’ setback from the creek. Benefits of the project include removal of invasive host plants for blue-green sharpshooters (mugwort, Himalayan blackberry, periwinkle, and wild grape), flood erosion protection, increased wildlife habitat and enhanced carbon sequestration.
About 20 years ago the creek got plugged and the whole vineyard and winery flooded - barrels floating. We built a berm and planted Cabernet Franc but the area has been highly susceptible to Pierce’s Disease, with weak vines requiring continual replanting. The idea is to save the strong vines on the south side by giving up the weaker, exposed vines, and we think on balance we’ll get more fruit.”
-Brad Smith, Winemaker, Silenus Winery
The RCD first piloted carbon farm planning on their own Huichica Creek vineyard located in Carneros. Their full Carbon Farm Plan is available online. RCD found that some of the conservation actions with the greatest carbon sequestration benefits were riparian restoration, compost application and reduced tillage. These specific practices also the biggest opportunities for Silenus.
In developing a CFP for Silenus the RCD and NRCS first inventoried the natural conditions on the farm and any opportunities to enhance carbon capture on the farm. The benefits of different actions were then quantified using USDA’s COMET-Farm and COMET-Planner and weighed against return on investment and funding opportunities.
Carbon provides the energy needed to drive on-farm processes, including the essential soil ecological processes that determine water and nutrient availability for the vines. Consequently, the CFP process views carbon as the single most important element, upon which all other on-farm processes depend.
Silenus Carbon Farm Plan — Top Five Practices for Carbon Sequestration and GHG reductions over 20 years:
- - Application of compost over 6.3 acres (10 tons/acre by end of year 5 and second application of 10 tons/acre beginning year 10) has the estimated potential to sequester 580 tons of CO2e
- Hedgerow planting in 1.52 acres has the potential to sequester 240 tons of CO2e
- Increasing cover crop from 60% to 75% cover area has the potential to sequester 40 tons of CO2e
- Planned riparian restoration practices on a 0.5 acre parcel have the estimated potential to sequester 10 tons of CO2e
- Implementation of alternate row tillage on 5.8 acres has the estimated potential to sequester 10 tons of CO2e
- Mulch application under the vines has the estimated potential to sequester 6 tons of CO2e
Altogether these five strategic Carbon Farm practices will sequester 886 tons of CO2e, equivalent to taking 188 typical cars off the road for a year. The compost application is also highly likely to result in enhanced vine and cover crop growth, capturing additional CO2. And the increased Soil Organic Matter will improve water infiltration.
We’re always learning. The RCD had funding for Carbon Farm Planning and we decided why not take advantage of it? The process has been valuable and streamlined. Learning about complex concepts like carbon sequestration can be overwhelming - need folks like the RCD and NRCS to help you. The whole team is excited to be able to tell this restoration story..
If you want to learn more about Soil Health & Carbon Farm Planning join us for a workshop hosted by Honig Vineyards on May 21 from 8:30 am to 12:30 pm (followed by box lunch). $25 per person and maximum of 30 guests.