Oasis Vineyard Biochar Trial
Citation: Hunt J, McIntosh C, Beck D, Baltar R (2023). Oasis Vineyard Trial Results – Harvest 2023 (7th leaf) Summary. Final draft, 12 December 2023. https://pacificbiochar.com/wp-content/uploads/Oasis-Vineyard-Trial_-5th-harvest_-Final-Draft_12.12.2023.pdf
What it is: A five-harvest summary of a vineyard trial on sandy, low-organic-matter soil in Monterey County, California, comparing compost, biochar, and both. It’s the vault’s best public dataset that combines yield and economics.
Key figures
| Figure | Value | Where | Check |
|---|---|---|---|
| Project | Began 2016 on a California Department of Water Resources grant: Sonoma Ecology Center (grant administrator), UC Riverside (principal investigator), Monterey Pacific (vineyard manager), Pacific Biochar (biochar supplier) | Trial summary PDF, p. 1 | ✓ full text |
| Site | 8 acres; mainly Oceano sand at 0.7% organic matter; Pinot Noir clone 456 on 1103P, planted 2017 | Trial summary PDF, overview | ✓ full text |
| Treatments (wet weight) | Control; compost 15 t/ac; biochar 10 t/ac; compost + biochar | Trial summary PDF, treatments | ✓ full text |
| Placement | Ripped down the vine row by GPS, mixed with a winged plow to 30 inches in a bowl about 2 ft wide × 2.5 ft deep | Trial summary PDF, overview | ✓ full text |
| Amendments as applied | Biochar 38% moisture, 75% organic matter (≈0.42% SOM gain in the row); compost 49% moisture, 43% organic matter (≈0.30%) | Trial summary PDF, overview | ✓ full text |
| Five-season total yield | Compost + biochar 41.7 t/ac; compost 40.1; biochar 38.2; control 31.7 | Trial summary PDF, results | ✓ full text |
| Average yield increase vs control | Compost + biochar +36%; compost +29%; biochar +25% | Trial summary PDF, results | ✓ full text |
| Grape quality | No significant differences | Trial summary PDF, grape quality | ✓ full text |
| Economics | Positive return by the 2nd harvest. By the 5th, extra revenue per acre of 12,569 (compost), and **1,500/t grapes (October 2023) and 2016 delivered prices of 240/t biochar (wet weight) | Trial summary PDF, economic impact | ✓ full text |
| Persistence claim | Woody biochar made above 600 °C; more than 80% projected to persist at least 100 years, citing models soil GHG from biochar | Trial summary PDF, carbon section | ✓ full text |
Use with care
- Not peer reviewed. The authors include McIntosh and Hunt, who also wrote the supplier’s explains biochar plus compost practice. The summary gives few statistical details.
- Revenue depends on the grape price. Water and fertilizer inputs were the same across treatments, so no savings are counted.
- Compost alone out-earned biochar alone; the combination did best.
Related: Agronomic Economics · Real World Soil Projects · Crop Yield Effects · Key Sources