The biodynamic preparations are something I feel to be highly worthwhile, but have no statistical evidence about.
The anecdotal reports from thousands of farmers suggest they have strongly beneficial qualities for soil and plants. But the way they work appears to be outside the realm of contemporary scientific measurement.
I come across scientists who are maddened by biodynamics because they cannot measure its effects or how it works: one professor declined to review my Myths book because it mentions biodynamics. Actually the Myths book has no mention of biodynamics but does mention planting by the moon, which is a separate thing altogether.
