Ferrington Vineyard is located on 167 acres of oak-woodland in the Anderson Valley, near Boonville, CA.
Demonstrating reduced tillage and cover cropping in Mendocino County provides access to growers and conservation staff that can speak directly to the benefits and challenges of practices, in terms of on-farm operation and economy, as well as their ecological co-benefits. These practices address operational and economic challenges such as soil compaction, erosion, weed pressure, and high fuel and labor demands. By reducing tillage passes and improving soil structure, growers may also save on fuel, labor hours, and equipment wear while also lowering repair costs from storm damage or erosion. Cover cropping at Ferrington has been shown to add nitrogen and increase water infiltration, and moderate soil temperatures, which is regionally important to consider due to increased drought frequency. Ecologically, cover cropping and reduced tillage mitigates sediment and nutrient runoff into salmonid streams, improves biodiversity through habitat for beneficial insects, and increases soil organic matter for carbon storage. These benefits align with watershed protection goals and resource conservation programs, making them attractive for both growers and policy partners.
This trial compares 5 commonly used plant cover systems (PCS) with different tillage and mowing combinations.
Starting in the spring of 2017, a tilled treatment with no cover crop planted was established on half of each of the plots with no-till and naturalized vegetation.
Ferrington Vineyards is a 167-acre property, half of which is vineyards, while the remaining oak-grassland hillsides are grazed by sheep. Steep, oak-grassland hills comprise 63 acres of the property and host a herd of 40 ewe sheep. The composition of the vineyard in 2020 was 48 acres of Pinot Noir, 15 acres of Chardonnay, 8 acres of Gewürztraminer, and 1 acre of Sauvignon Blanc. The vineyard uses bilateral cordon training and spur pruning, and outside of the demonstration area is managed under a three-year alternate row tillage regime. Every other row is planted in subterranean clover and left as a permanent cover for three years. The other half of the rows are planted annually with a green manure blend of bell beans, peas, vetch, oats, and wheat and then plowed under. An olive tree shelterbelt, apple trees, and multistory cropping in various locations were established between 1997 and 1998, covering approximately 1.5 acres.
Norman Kobler, the land manager, is a local, multigenerational grapegrower who enjoys experimenting with enhancing his vineyard’s high-quality grapes, water use efficiency, ecosystem resiliency, and overall sustainability. He has been consistently interested in keeping the trial going as long as he can.
Along the south end of the demonstration site, there is a 15-50 foot buffer to an unnamed tributary to Anderson Creek and riparian zone, though testing has shown the soil on the south end of the demonstration block is not significantly sandier or wetter. The soil map units that overlap on the demonstration site are very similar. Soil sampling was limited to the first 180 feet of each row to reduce variability, and neither end of the trial block included a field edge.
Over the near-decade of this demonstration site running, compost has been applied to all treatments equally once as part of a Healthy Soils Program grant. There are no other intersecting or confounding conservation practices in the demonstration areas.
The elevation at Ferrington Vineyard ranges between 387 feet at the valley floor and 685 feet at the top of the hills. The trial is on the valley floor close to 387 feet.
Map Unit | Slope | Soil Texture | Organic Matter (%) | AWHC (cm/cm) | Depth to Root Restrictive Layer |
109 | 2-9% | Loam | 2.5 | 0.15 | 60 |
193 |
Positioning: North to South
Grape Varietals: Pinot Noir, Sauvignon Blanc, Gewürztraminer, Chardonnay
Clones: 667/777, 115, 828, Pommard
Rootstock: 101-14, SO4
Vine spacing: 7 feet by 5 feet
Vine age: The Ferrington vineyard was originally planted in the late 1960s although some of the 25 acres of Pinot Noir vines were planted in 1998 and some even more recently.
Irrigation system: Elevated drip irrigation with overhead microsprinklers for frost protection
This trial began in 2015. The original monitoring period was 2015-2022. Additional data was collected in 2024 and 2025. Current funding for MCRCD soil sampling and field assessments ends in 2025 and opportunities for continued monitoring are being explored, and the landowner will keep the trial implementation going into the future at least several more years. The project is 7 acres, 4 replicates of 4 treatments, completely randomized.
Mendocino County RCD
USDA-NRCS
UCSAREP
North Coast Soil Hub
Ferrington Vineyard
MCRCD staff and NRCS are collecting soil and water data, Ferrington Vineyard collecting plant and yield data.
Variable | Method/Equipment | Frequency |
Vine water status | Pressure chamber | 2016, 2017 |
Vine yields and pruning weights | 3 times throughout first trial period (2017, 2018, 2020) | |
Soil Compaction (to 36”) | Penetrometer | Annually, in spring |
Water Infiltration | Measured in vine rows, tire tracks, and between rows using ring infiltrometer method | After 2 years, after 3.5 years, after 9 years, after 10 years (annually in 2024 and 2025) |
Soil Health Testing (aggregate stability, bulk density, total carbon and nitrogen, permanganate oxidizable carbon, mineralizable carbon, and potentially mineralizable nitrogen) | Measured in between rows | After 2.5 years, after 5.5 years (annually in 2024 and 2025) |
Measured in vine rows | ||
Oregon State University’s complete soil health lab assessment (pH, EC, Organic matter, CN, NO3-N, P, K, Mg, Ca, texture, potentially mineralizable N, active carbon, wet aggregate stability, respiration) | https://cropandsoil.oregonstate.edu/shl/testing-services/soil-testing | Annually during funded trial periods (2015-2022, 2024-2025) |
Original Data Collection (2015-2022)
Check out a summary of the Ferrington Vineyard Field Trial written by Ukiah NRCS and Mendocino County RCD here.
Seth Myrick, Sustainable Agriculture Program Manager, MCRCD
seth.myrick@mcrcd.org
Norman Kobler, Farm Owner, Farm Manager
norman@philovineyard.solutions
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