13/06/2026
🪱 Practical Biodynamic Success: 38% More Earthworms in Biodynamic Systems?
A 2023 analysis of more than 100 UK studies, spanning almost a century, suggested that earthworm abundance may have declined by around 33–41% over the last 25 years: https://buff.ly/6YuWXpc
In the 45-year DOK Trial in Switzerland — one of the world's longest-running comparisons of biodynamic, organic and conventional farming systems — researchers found substantially more earthworms in the biodynamic plots.
During the 1990–91 measurements:
🪱 Biodynamic plots contained **302 earthworms per m²
🪱 Conventional plots contained **219 earthworms per m²**
That's **38% more earthworms** in the biodynamic system.
Earthworm biomass was also higher:
🪱 Biodynamic: **192 g/m²**
🪱 Conventional: **154 g/m²**
That's **25% greater earthworm biomass**.
Researchers note that some conventional plots initially used plant protection products that were highly toxic to earthworms, contributing to lower earthworm numbers and biomass in the early years of the trial.
Why does this matter?
Earthworms are among the most important soil animals. They help improve soil structure, increase water infiltration, mix organic matter into the soil and support nutrient cycling and plant growth.
When earthworms thrive, it's often a sign that the wider soil ecosystem is thriving too.
👉️ Source: FiBL (2024), *The DOK Trial: A 45-Year Comparative Study of Organic and Conventional Cropping Systems*, pp. 38–39: https://buff.ly/MDFEFRb
