Barrel compost

What is barrel compost?

Barrel compost (German: Fladenpräparat) goes back to Maria Thun and is a kind of collective preparation: prepared cow manure to which basalt rock dust, crushed eggshells and the six compost preparations (502–507) are added. The mixture matures over several weeks in a container (or a shallow pit), is worked through several times, and is then diluted, stirred and applied. Maria Thun developed it in the 1970s.

It serves to guide decomposition: to enliven the soil and for surface composting. Unlike the individual compost preparations, which go into the compost heap, the finished, stirred barrel compost can be spread over the whole area and so takes the effect of the compost preparations to places where there is no prepared compost (yet).

Making it and what goes in

The classic mixture consists of fresh cow manure with coarse basalt rock dust and crushed eggshells added. According to Pierre Masson, the manure and additions are mixed thoroughly for about an hour, ideally turned over by two people with shovels, as when mixing mortar. The mass then matures with the compost preparations added and is turned repeatedly while it matures. The result is a crumbly, humus-like mass.

How it matures

Maturing follows a fixed rhythm. The cow manure is set up with basalt rock dust and eggshells in a barrel (or a shallow pit) and treated with the compost preparations. After about four weeks, the contents are dug over and moved with a spade for an hour without a break, and treated again; after about another two weeks, the barrel compost is ready to use. The result is a dark, crumbly, humus-like mass.

Effect and use

According to Wistinghausen, barrel compost is expressly an intensification of the effect of the compost preparations and is not to be confused with horn manure (500). To use it, about 60 grams in 10 litres of water are enough for a quarter of a hectare; it is stirred (like a spray preparation) and applied to soil and land. The best effect on soil processes comes from three sprayings made over one to two days from the same stirring, especially in autumn after harvest and when preparing the soil. In Demeter practice, it also serves as a substitute when no prepared farmyard manure is available (for example in the first year of conversion, or on horticultural holdings without livestock).

Related collective preparations: birch pit and decomposition guides

Barrel compost belongs to the family of collective preparations that take the forces of the compost preparations over the land in concentrated form. Closely related is the birch pit preparation: a manure compost prepared in a pit lined with birch wood. Depending on how mature it is, it serves as a collective preparation (after one to three months) or as manure water (after six months to a year), and is added in very small amounts to manure, slurry or compost to stimulate decomposition. Another well-known variant is the "Mäusdorf decomposition guide" (Mäusdorfer Rottelenker). All these preparations share the idea of making prepared cow manure with the compost preparations usable as a decomposition guide that works over the whole area.

Barrel compost and cow pat pit: not the same thing

Often confused, but to be kept apart: Maria Thun's barrel compost is not the same as the cow pat pit (CPP). The CPP goes back to Peter Proctor, who developed the method further mainly for tropical and subtropical climates; it typically matures in a pit. In English-language sources the two names are sometimes used as synonyms. Both rest on the same idea, prepared cow manure with the compost preparations, but they are different methods with different origins and suited to different climates.