How can growers repeat the BD 501 material comparison?

Prepare separately labeled horn silica from finely ground quartz and orthoclase feldspar, apply each at the same rate and timing to matched plots, and retain an untreated or standard-practice plot. Record soil type, weather, crop growth, yield, quality, and photographs across more than one season.

What BD 501 variables does Hugh Courtney propose testing?

He discusses quartz versus orthoclase feldspar as horn-filling material, very fine grinding, possible iron introduced by an iron pestle, and soil-specific choices such as feldspar for sandy soils. Each variable can be isolated in labeled batches and compared under the same field conditions.

What procedures did the introductory workshop document?

Participants stirred BD 500 and BD 501 for one hour, BD 508 and Barrel Compound for twenty minutes, repeated spray-and-rake exercises three times, and inserted BD 502–507 into compost. The clearly stated timings make the workshop method reproducible.

How should the amethyst-spray account guide a repeatable trial?

Use matched cabbage plots, hold mulch, irrigation, liquid ferment, and Barrel Compound constant, and vary only the amethyst spray. Record plant count, leaf area, pest damage, head weight, and harvest date before repeating the trial.

Applied Biodynamics archive

Applied Biodynamics — Issue 012 (Summer 1995)

Issue 012 (Summer 1995) examines BD 501 material choices, a JPI workshop, an amethyst-spray field report, and Chris Stearn’s research ambitions.

December 30, 2025 Published by The Josephine Porter Institute Download PDF

Applied Biodynamics Issue 012 (Summer 1995) focuses on horn silica (BD 501), an introductory JPI workshop, an amethyst spray report, and an interview with incoming assistant director Chris Stearn. It is most useful as a record of questions, methods, and practitioner claims—not as proof of efficacy.

Horn silica as a set of hypotheses

Hugh Courtney’s “BD #501—The Horn Silica Preparation” returns to Steiner’s wording that a horn may be filled with finely ground quartz or with orthoclase feldspar. Courtney treats source material as a variable: quartz for many situations, and a feldspar form for predominantly sandy soils because of its potassium, calcium, sodium, and clay relationships. He explicitly calls the sandy-soil proposal a “theoretical construct” and says it needs practical testing.

The article also discusses grinding quartz to a very fine powder, Steiner’s mention of an iron pestle, and Courtney’s speculation that iron incorporation might matter. It describes past use of an unground quartz-sand or rectorite material and reports a striking potato-beetle observation after spraying, but no untreated comparison, counts, or repeat trial are supplied. Courtney’s language about lime–silica polarity, the plant “diaphragm,” iron and the Archangel Michael, and a full growing zone belongs to biodynamic and anthroposophical interpretation.

The surviving pages argue that BD 501 horn silica should complement BD 500 horn manure, yet they also acknowledge that effects may be subtle and hard to observe. The material choices are presented as hypotheses for soil-specific field comparison rather than as a universal formula.

What the introductory workshop actually taught

Erin Coffin reports that thirty participants and nine staff or volunteers attended JPI’s April 29, 1995 workshop. Four groups practiced stirring: BD 500 and BD 501 for one hour each, and BD 508 horsetail and Barrel Compound for twenty minutes each.

Participants sprayed Barrel Compound and BD 500 on garden-bed sections and raked the soil, repeating the spray-and-rake sequence three times. Comments that treated soil felt “silky” or “smoother” are subjective impressions, not blinded measurements. The workshop also demonstrated insertion of the BD 502–507 compost preparations: BD 502–506 were placed in designated holes with compost, while valerian liquid was partly poured into its hole and the remainder sprayed over the pile.

A question-and-answer handout covers containers, acre-sized units, Barrel Compound frequency, compost maturity, storage, tap-water chlorine, calendars, and the distinction the authors draw between organic and biodynamic practice. These details document JPI’s teaching method; participant enthusiasm and tactile impressions do not test preparation effects.

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