2.4.4.c.b What are the preparations that are specific to biodynamic agriculture?

500: Horn manure is made from cow manure that ferments and then matures inside a horn buried in the soil during the winter period (October to April). The cow horn enables a 70 times higher content of micro-organisms in the dung than if it were placed in a simple glass jar. Presented by Rudolph Steiner in his "Agriculture Course", the 500 preparation focuses on the plant's root system, improving soil structure and microbial life, strengthening root growth and development, and enabling, among other things, better resistance to drought.

Compost preparations: These are six preparations usually used for compost, numbered from 502 to 507. These preparations encourage certain processes in the soil and plants, notably through the mobility of macroelements in the soil (phosphorus, nitrogen, potassium, etc.).

500 P: Prepared horn manure or 500 P, the result of research by the Australian Alex Podolinski, is a preparation based on "classic" horn manure (500) with additional compost preparations. A few months after removal from the soil, the horn manure is supplemented with compost preparations (502 to 507) and becomes 500P. 500P is significantly more effective than horn manure by itself. These preparations have effects on the roots and the soil, enhancing the soil structure, microbial activity, and humus formation. They help regulate the soil's ph, generally strengthen the root growth system and its development and consequently stimulate the plant's overall growth.

Maria Thun's barrel compost: a preparation of cow dung combined with basalt and fresh eggshell that is then aged in a barrel. 240 grams of compost per hectare are stirred in water for 20 minutes. This preparation should be combined with preparation 500.