The cornerstone of Biodynamics is preparation 500, this is a horn manure field spray and it is working with the earth and vigour and the horn silica field spray works with form and light. 500 is used to improve soil structure and microbiological activity. Spraying the horn manure stimulates soil bacteria, which promotes soil fungi, which in turn enable nutrient exchange between the plant roots and the soil.
This is made by stuffing finely-ground quartz (silica) into cow horns, burying those horns over summer, then stirring a very small amount (just a couple of grams) of the powder in rain water for an hour and spraying the resulting liquid in a fine mist over your farm. The purpose of 501 is to complement the earthy forces of the 500 and attract light forces to the plant.
Made from combining a part of a plant or herb and a part of an animal and left for several months to break down. There are six in number and are used in all composts (liquid and solid) They assist in the composting process.