Resources to build soil health and resilience on farms in California's North Coast region.

Summer 2026 | Edition 24

Updates on Regional Field Trials & Demonstration Sites

New Agroforestry Demonstration Site

In 2025, Soil Hub member Marin RCD established a new agroforestry demonstration site as part of a grant supporting the CA Farm Demonstration Network. The project seeks to fill a knowledge gap around silvopasture, broadening local understanding of effective design, installation, and maintenance. The demonstration site was developed to build regional knowledge about silvopasture systems, particularly “silvopasture by addition,” or adding trees to grazing systems. The demonstration project will help landowners to assess trade-offs and evaluate common concerns associated with mixed agroforestry-grazing systems.

Exploring Biochar and Compost Synergies in Napa Vineyards

By: Miguel Garcia, Senior Agriculture Project Manager at Napa County RCD

In 2021, with funding from the Western Sustainable Research and Education Program, a vineyard trial was launched at Beaulieu Vineyard in Rutherford to test a simple question: Can biochar and compost actually improve soil health in Napa vineyards? The vineyard trial site, a young Cabernet Sauvignon block with low organic matter and stressed vines, was chosen because it reflects what many growers in the North Coast face. The project, led by Napa County RCD and Treasury Wine Estates, compares four treatments side by side: compost, biochar, compost + biochar, and a control with no amendments.

Annually, we are measuring soil organic matter, microbial activity, water retention, and vine performance, and will continue to track these metrics over time, recognizing that meaningful improvements in soil health can take many years to emerge.

So far, the preliminary results are promising:

• Compost and biochar together are storing the most carbon, nearly 11 times more than the control, or close to 8 tons in total. This is an early sign of potential long-term climate benefits.
• Compost alone shows the strongest early improvements in soil structure and active carbon, both indicators of growing microbial activity and fertility.
• The compost + biochar plots show slightly higher soil respiration, hinting at more active soils that may continue developing over time.

While it is still early to link these changes to grape yields or quality, initial results suggest that compost is improving soil health, and that biochar may be enhancing those benefits. We will continue to monitor these trends in soil health to confirm the long-term impact of compost and biochar amendments.

New Cover Crop Species Selector Tool from Western Cover Crops Council

It's the time of year to think about planting cover crops - here's a resource to support species selection based on site conditions and goals:

Vineyard Sheep Grazing Guide from Community Alliance with Family Farmers

This best management practices guide has been developed to facilitate integrating sheep into vineyard systems in California. While every operation is different with regards to management practices, site, goals and available resources, land managers can use this guide for grazing in combination with a variety of other soil health practices to achieve their management, financial and environmental objectives. This guide is a product of collaboration between vineyard managers, extension specialists, graziers, Community Alliance with Family Farmers, the Agroecology Lab at UC Davis, the Ecdysis Foundation, and the Napa Resource Conservation District. The guide is available in English and Spanish.

Resources for Land Managers and Technical Service Providers Conducting USDA-NRCS Soil Health Testing

The North Coast and Sacramento Valley Soil Hubs partnered to produce video guides on how to perform soil sampling for the USDA Natural Resources Conservation Service Regen Ag Pilot Program. You can find the videos on our website as well as on YouTube here: