Barrel compost after Maria Thun: making it, using it, Demeter rules

Barrel compost after Maria Thun (in German "Fladenpräparat", cow pat preparation) brings the six compost preparations onto the land. It is used wherever no prepared manure and no prepared compost reaches: on arable land and meadows, in slurry, on the manure bedding in the barn, under green manure before it is worked in. The Demeter standards require it as a collective preparation in the first year of conversion and in market gardens and permanent crops without their own manure from ruminants.

It is stirred for 15 to 20 minutes, stays sprayable for three days afterwards and is applied three times. 240 grams are enough for one hectare.

This article gives the original recipe with all quantities, its use on the farm and in the garden, the passages in the Demeter standards and the difference from Cow Pat Pit and the Mäusdorf decomposition guide.

What barrel compost is

A collective preparation, also called a decomposition guide. Fresh, firm cow manure is worked through by hand for an hour with basalt sand and ground eggshells, prepared with the compost preparations and brought to maturity in a wooden barrel or a pit. The result is stirred and applied like a field spray preparation.

Maria Thun put a sentence before her original description that clears up the most common confusion to this day:

"The reader should note that the following description is not about horn manure preparation 500, but about intensifying the effect of the compost preparations."

Maria Thun, "Hinweise aus der Konstellationsforschung", translated from the German

Horn manure 500 acts directly on the plant and is given at sowing. Barrel compost works on the transformation of organic matter. If you have both, one does not replace the other.

Why eggshell and basalt

The two unusual ingredients have a history. After the atmospheric atomic bomb tests from the late 1940s, radioactive fallout came down over the fields of Europe. Ehrenfried Pfeiffer feared that the making and the effect of the preparations would suffer. He and Maria Thun looked for an answer.

Studies by an institute in Freiburg had shown that plants from soils weathered from limestone took up far less of these substances than plants from the siliceous soil of the same landscape. Thun pursued the matter for years. She crushed various substances to a grit-like consistency and put them into the seed drills and planting holes of celeriac, spinach and tomatoes. The result was clearest with hen's eggshell. Bone meal and seaweed lime worked less strongly. Basalt, as she wrote, took "a certain harmonious position between the calcareous and the siliceous side".

This became the additives of barrel compost. The ground eggshell stands for the calcium processes in the soil and the regulation of pH. Basalt, as sand, brings ever new weathering processes into the soil, which benefit the binding of clay minerals, and when strewn directly in the barn it binds nitrogen. As carrier material for all three aspects Thun chose the cow pat. She developed the preparation, in her own words, "as an enlivening factor for radioactively contaminated soils".

The recipe was first published in 1972 in the "Hinweise aus der Konstellationsforschung". Nothing about it has changed since. Thun did not even try other sizes and weight ratios, because her other trials had shown that when the ratios change, so do the effects.

The note that came with every delivery for years

Wedig von Bonin made barrel compost for about 30 years at Hof Eichwerder in East Holstein, in close exchange with Maria Thun. It was his favourite preparation. In 1968 he had converted the farm to biodynamic farming and made his first trials with it at that time.

Because more and more people asked for it, in 2007 he and Simon founded the first preparations partnership and presented the first online shop for biodynamic preparations in Dornach. The shop was called fladenpraeparat.de and stocked only this one preparation.

A note came with every delivery: Thun's own description, on one page, from the carrier material to spraying after the paddocks have been grazed. It is still made today, to the same recipe, measured against the same standards.

The original recipe

The quantities come from Thun's own account. Christian von Wistinghausen gives them word for word in "Anwendung der Feldspritz- und Düngerpräparate"; Pierre and Vincent Masson give the same quantities with small differences in execution.

Ingredients for one batch

The procedure

1. Mixing. Cow pats, eggshell and basalt sand go into a round wooden tub. Turn and move them with a spade for an hour; this is the dynamisation. Ideally two people shovel, as when mixing mortar. Thun walked around the container and insisted on handwork: the substances should be regarded as something that becomes a kind of organism as it is completed, and in the making of an organism she wanted to do without machines as far as possible. Anyone preparing larger quantities for a group uses a concrete mixer in practice.
2. Prepare the vessel. A wooden barrel without a bottom is dug in 40 to 50 centimetres deep, with the spoil banked up around it. Durable larch or leached oak are suitable, rusting iron hoops are not. Thun preferred round vessels, because faulty fermentation easily arises in corners. For the site she avoided lines of force and veins in the ground.
3. Prepare the first layer. Fill in half the mass, make five holes to half its depth and put one portion of the solid compost preparations into each, about two grams. Stinging nettle in the middle. Close the holes.
4. Prepare the second layer. Fill in the rest, make holes in the same arrangement, set the same preparations above in the same order.
5. Valerian. Stir five drops of valerian preparation in one litre of water for ten minutes, pour over the mass, also around the barrel.
6. Cover. A wooden lid or board on top. The barrel stands outdoors.
7. Turn after four weeks. Turn and move the contents with a spade without interruption for an hour, then prepare again.
8. After another two to three weeks the preparation is ready. It is mature when it has become blackish, loose and crumbly and has lost the smell of fresh manure. Max Karl Schwarz described the smell of his birch pit preparation as a scent of porcini mushrooms. If you make larger quantities or work late in the year, let it mature longer.

It is set up between spring and late summer, free of frost. Thun recommended days with the Moon in Leo or Virgo for setting it up. On many farms setting it up is anyway a day of its own in the year, when the preparation group comes together.

What can go wrong

Michael Maltas compiled the following points after a batch that failed. They cover most cases in which barrel compost does not mature:

• Too large a quantity at once. Above 200 litres, conditions inside become anaerobic, a crust forms on top, and underneath lies unchanged manure. Smaller batches succeed more reliably.
• Too dry. Set up in the heat of high summer and not watered, the transformation does not get going.
• Fresh oak as a container. The tannic acid holds back the microorganisms. Leached wood is fine.
• Angular vessels. Faulty fermentation arises in the corners.
• The site. Do not place it next to trees whose roots grow into the pit. Under a black walnut the soil dries out, and its root exudates come on top.
• Manure from cows fed concentrates. The pat becomes too soft and forms poorly.
• Too few preparations for the amount of manure. Each layer needs a complete set.

Use

Stirring

15 to 20 minutes, alternately clockwise and anticlockwise, as with horn manure and horn silica, but only a third of the time. Lukewarm rainwater if possible. Thun described this shortening explicitly as rationalisation: thanks to the dynamisation when setting up, the work has already been done at the front end. The whole technique of stirring is described in Stirring the preparations.

After stirring, the liquid remains effective for at least 72 hours. That is the great practical advantage over horn manure, which needs to be applied within two hours. Barrel compost is also forgiving about water quality and sprayer. Three applications from a single stirring are therefore easily possible.

Quantities

Three times, not once. Three sprayings from the same stirring show the best effect on soil processes. That is part of the recipe, not overcaution. Thun and Throll recommend evening, morning, evening, or three consecutive days. If you work with the constellations, place the three applications in one trigon of the sidereal lunar rhythm.

When in the year

• With every application of manure, compost and slurry, to stimulate transformation.
• When working in green manure, crop residues and mulch, for stubble cultivation, for breaking up clover grass and for winter ploughing.
• On grassland after the paddocks have been grazed, after cutting for hay or silage and after the last use in autumn.
• In fruit growing after a compost application, when shredding prunings and before leaf fall, so that the fallen leaves break down quickly.
• In the barn, poured over the manure pad daily or weekly.
• In vegetable growing as a compost starter for farmyard manure and on all areas that receive neither manure nor compost.

In the home garden, twice in March before sowing and once in November after harvest has become established.

On the farm a front tank saves an extra trip: spraying is done while other work is being done anyway.

What it is used for

Barrel compost is used as a decomposition guide, wherever organic matter is to be transformed. Biodynamics recommends it to stimulate the transformation of manure, compost, slurry, green manure and crop residues, to support humus formation and to promote the binding of organic matter with clay minerals. On grassland it is sprayed after grazing and after cutting to stimulate the transformations in the meadow soil. In the barn it is poured over the manure bedding; it goes into slurry together with bentonite so that decomposition is guided early and the nitrogen stays in the cycle.

On arable land it is used for ploughing, for stubble cultivation, for breaking up clover grass and whenever a lot of organic mass goes into the soil. Gyso von Bonin used it in exactly this way.

Maria Thun ends her original description with a sentence about which nothing has changed since: "It can be most warmly recommended to the practitioner."

Xavier Florin counted barrel compost among the three supporting rungs of the biodynamic ladder. For him it stood for the compost preparations as a whole, and that is exactly its task: it brings them onto the land, even where no cow stands.

What was measured in Braunschweig

Over ten years Maria Thun worked with the Federal Agricultural Research Centre (FAL) in Braunschweig. Involved there were the Institute of Plant Nutrition and Soil Science under Ewald Schnug and the Institute of Organic Farming, with the Egyptian SEKEM initiative as a further partner. Schnug headed the institute from 1992 and is a professor at the Technical University of Braunschweig; later he took over the Institute for Crop and Soil Science at the Julius Kühn Institute. Uranium in phosphate fertilisers is one of his own fields of research.

A trial concerning barrel compost comes from this cooperation. In grass from soil treated with barrel compost, the uranium content averaged 0.5 milligrams per kilogram, compared with 1.8 in the controls. The FAL called the difference clear and significant. The associated pot trial goes back to Susanne Schrötter, Ewald Schnug and Maria Thun.

For Maria Thun this closed a circle. She had developed the preparation decades earlier for exactly this question and at that time had struggled to get any measurements at all.

Barrel compost in the Demeter standards

In the Demeter standards 2026 barrel compost is named explicitly in four places and as a "collective preparation" in two more. That is why conversion farms and market gardens regularly ask about it. The passages below refer to the German Demeter e. V. standards; farms in other countries check the standards of their national Demeter organisation.

Crop production, chapter II.2.4 paragraph 3. The compost preparations are to be used in all organic farmyard manures and composts. If no prepared farmyard manure is available in the first year of conversion, a collective preparation must be applied on all areas.

Crop production, chapter II.2.4 paragraph 4. Market gardens and permanent crop farms without prepared ruminant manure must additionally apply a collective preparation at least once a year on all areas.

Livestock, chapter II.3.1 paragraph 3. Permanent crop farms and market gardens under ten hectares are exempt from the requirement to keep livestock. If they have no prepared ruminant manure, they must, in addition to the compost preparations, apply "barrel compost or similar" at least once a year on all areas.

Conversion, chapter II.6 paragraph 4. Anyone who wants to label products as "in conversion to Demeter" or "Demeter" in the same year must have entered the certification procedure by 1 May. By then horn manure or barrel compost must have been applied on all areas, and horn silica as suits the crop before harvest.

Plant breeding, chapter II.5.2 paragraph 2. If breeding takes place on recognised organic fields, horn manure and horn silica are to be applied at least once a year as suits the crop, and prepared compost or, as a substitute, barrel compost is to be applied on all areas.

Bought-in feed, chapter II.3.5.5 paragraph 1. Organic feed from neighbouring organic farms only counts as the Demeter farm's own share if there is a usage agreement for at least three years and the Demeter farm has arranged for the preparations, including barrel compost, to be applied throughout the whole crop rotation.

The wording "or similar" and the umbrella term collective preparation leave room for the related preparations. What counts for your own certification is the current version of the standards and the information from the responsible inspection body.

The family of collective preparations

All the following recipes share the same idea: prepared cow manure becomes, with the compost preparations, a decomposition guide that can be brought onto the land.

Barrel compost, Cow Pat Pit and the Mäusdorf decomposition guide compared

In India Peter Proctor recommends much more frequent use than is usual in Central Europe, monthly or every two weeks. Anyone reading international guides should therefore not adopt the quantities unchecked.

Cow or horse

Besides the cow version there is barrel compost made from horse manure. Thun recommended it where manures that decompose poorly arise, for example from bulls or pigs, and set it up when the Moon stood in Virgo. Bernard Jarman sees horse manure as the right one for cold sites and heavy soils: it brings new life into them.

In viticulture the horse version has proved itself because it stimulates leaf development less than cow manure. In vines, too much leaf mass is undesirable.

Storage

Mature barrel compost often stays in the barrel it was set up in. That works if it is used soon. For longer storage it belongs, like horn manure, in a vessel of stoneware, glass or enamelled metal, placed in a double-walled wooden box filled with peat or coconut fibre. Cool and dark.

It does not belong in plastic permanently. If it is delivered in plastic, transfer it on arrival.

Compared with the field spray preparations, barrel compost is robust. It also forgives less favourable storage conditions, because it is closer to compost than to a preparation in the narrow sense.

Make it yourself or buy it

For your own batch you need access to cow manure from biodynamic or at least organic husbandry, a set of compost preparations, basalt sand of the right grain size and about eight weeks' lead time. The effort lies less in the material than in the hour of mixing and the turning after four weeks.

On many farms the preparation is made in a group, in the preparation circle or on a shared preparation day. Five buckets of pats, two people at the shovels, one hour: this is work that goes better with two than alone.

If you do not set it up yourself, you can buy it ready-made. The packs of the Präparatekiste are sized by area:

In addition there are the sets in which barrel compost comes together with the field spray set or the complete canon 500 to 508, and the basalt sand for everyone who sets it up themselves.

Frequently asked questions

What is barrel compost?

A biodynamic collective preparation made from cow pats, basalt sand and ground eggshell, prepared with the compost preparations 502 to 507 and matured in a buried wooden barrel. It is stirred and sprayed and brings the power of the compost preparations onto the land.

What was it developed for?

Maria Thun developed it in cooperation with Ehrenfried Pfeiffer as an enlivening factor for soils that had received radioactive fallout. The two additives eggshell and basalt come from this work.

Has barrel compost been studied?

Yes. Maria Thun worked for over ten years with the Federal Agricultural Research Centre in Braunschweig, among others with the Institute of Plant Nutrition and Soil Science under Ewald Schnug. In grass from soil treated with barrel compost, the uranium content averaged 0.5 milligrams per kilogram compared with 1.8 in the controls.

Is barrel compost the same as horn manure 500?

No. Horn manure is given to the soil at sowing and acts directly on the plant. Barrel compost intensifies the effect of the compost preparations and works on the transformation of organic matter. Maria Thun explicitly put this confusion at the start of her original description.

How much do I need?

240 grams per hectare in 35 to 50 litres of water. In the home garden 20 millilitres in two litres of water for 200 square metres.

How long must I stir?

15 to 20 minutes, alternating in both directions. Horn manure and horn silica need an hour, barrel compost about a third of that.

How long does it keep after stirring?

At least 72 hours. That is why the recommended three applications can be made from a single stirring.

When do I apply it?

Whenever organic matter goes into the soil or is to be transformed: with manure and compost, when working in green manure and crop residues, for winter ploughing, on grassland after cutting, in the barn on the manure bedding.

Do I need it for Demeter certification?

That depends on the type of farm. Market gardens and permanent crop farms without prepared ruminant manure must apply a collective preparation on all areas every year. During conversion, horn manure or barrel compost must have been applied on all areas by 1 May. The details are in the Demeter standards, chapters II.2.4, II.3.1 and II.6.

What is the difference from Cow Pat Pit?

Cow Pat Pit goes back to Peter Proctor and is the variant for tropical and subtropical regions: shallow brick pits, locally available rock dusts, much higher application rates. The same basic idea, a different method.

What is the difference from the Mäusdorf decomposition guide?

The decomposition guide is dried and ground and can be strewn. Its focus is decomposition in slurry, manure and deep litter. Barrel compost is stirred and sprayed, with its focus on the soil and the land.

Can I make it myself?

Yes, the recipe is published and given above. You need cow manure from suitable husbandry, a set of compost preparations, basalt sand, a wooden barrel and about eight weeks.

Cow or horse manure?

Cow manure is the rule. Maria Thun recommended horse manure for farms with manures that decompose poorly; in viticulture it is used because it stimulates leaf development less.

How do I store it?

Cool, dark, in stoneware, glass or an enamelled vessel, ideally in a wooden box filled with peat or coconut fibre. Not permanently in plastic.

Sources

• Maria Thun: Das Fladenpräparat. In: Hinweise aus der Konstellationsforschung. First publication of the recipe 1972; here after the version that came with deliveries from the Präparatekiste (extract from the 8th edition). Reference for the third edition 1977, pp. 33–35, in Stappung.
• Maria Thun, in: Lebendige Erde 28/6 (1977), pp. 214–219 (quoted after Stappung).
• Maria Thun (1994), pp. 109, 111, 147; Maria and Matthias Thun (2012), pp. 56–59 (quoted after Stappung).
• Christian von Wistinghausen et al.: Anwendung der Feldspritz- und Düngerpräparate, chapters 5.1, 5.3 and 5.6.
• Pierre and Vincent Masson: Landwirtschaft, Garten- und Weinbau biodynamisch (2015), pp. 61–68.
• Walter Stappung: Die Düngerpräparate Rudolf Steiners. Herstellung und Anwendung, chapter 18.
• Demeter standards 2026, chapters II.2.4, II.3.1, II.3.5.5, II.5.2, II.6.
• Peter Proctor, on Cow Pat Pit; Varadarajan Stalin et al. (2010) on the microbiology of CPP (quoted after Stappung).
• Bundesforschungsanstalt für Landwirtschaft (FAL), Braunschweig: "Eine Begegnung der anderen Art. FAL-Wissenschaftler prüfen Präparate und Methoden biologisch-dynamischer Landwirtschaft", press release of 1 August 2006 (Institute of Plant Nutrition and Soil Science, Ewald Schnug and Silvia Haneklaus, with Maria Thun and SEKEM).
• Susanne Schrötter, Ewald Schnug, Maria Thun (2007), pot trial on uranium uptake (quoted after Stappung).