Horn manure (500)
Biodynamics’ signature soil preparation.
Horn manure (preparation 500) is the central soil preparation of biodynamics. Cow manure is fermented inside a horn buried over winter, producing a dark humus that is then dynamised in water and sprayed onto the soil.
It is applied in small quantity, typically at the end of the day and on root days, to stimulate biological activity, structure and rooting. In biodynamic practice it is the founding gesture of soil work and a requirement of Demeter certification.
Effort
Medium — dynamising and applying a few times a year.
Cost
Low — small quantities; can be made on the farm.
Time to result
Gradual soil effect over several seasons.
What it advances
Contribution by goal — click through for detail and metrics.
It is biodynamics’ central soil preparation, applied to stimulate biological activity, structure and rooting.
Using 500 is mandatory under Demeter; each application must be logged and traceable for the audit.
By favouring rooting and a living soil, practitioners associate 500 with more balanced vines.
Making 500 on the farm ties into the animal cycle and the self-sufficient farm-organism concept.
How it works
The preparation is dynamised in water (alternating stirring) and sprayed in coarse droplets onto the soil; practitioners use it to stimulate biology and rooting.
How to apply
- 1Dynamise the preparation in warm water for an hour.
- 2Spray onto the soil at day’s end, in coarse droplets.
- 3Favour root days and the descending calendar phase.
- 4Log rate, plot and date for certification.
What to measure
Frequently asked
When is 500 applied?
Typically in the late afternoon/evening, on root days and descending-sap phases, over moist soil — a few times a year.
Can I make 500 on my own farm?
Yes — many growers bury the horns and make the preparation, which reinforces the self-sufficiency Demeter values. Ready-made preparation can also be bought.
Related reading
Related practices
How GrapeFlow helps
Plan and document this practice by plot, with an audit-ready history for Demeter certification.
Biodynamic calendar
Root, leaf, flower and fruit days and the lunar phases in GrapeFlow, to plan preparation applications and work in step with the calendar.
Preparations & application log
Every application of 500, 501 and the other preparations logged by plot, date and rate — the history the Demeter audit asks for.
Electronic field notebook
All operations — compost, cover, animals, dynamisation — logged by plot, ready for certification.