What is Preparation 501?

• A. Horn Manure: cow manure stored in a cow's horn, buried, then dynamised and sprayed onto the soil
• B. Horn Silica: cow's horn filled with ground quartz (silica) and buried, then dynamised and sprayed onto the soil
• C. Compost tea
• D. Yeast culture

Answer: (B)

Preparation 501 is the biodynamic preparation made from silica (ground quartz) placed in a cow’s horn, buried through the winter, then unearthed and prepared as a liquid to spray on crops. Its purpose is to enhance the plant’s ability to harness light and support healthy growth, often applied as a spray on foliage or soil after vigorous mixing (dynamising). This distinguishes it from the other options: Horn Manure is the 500 preparation used to stimulate soil life and fertility; compost tea and yeast culture are not the 501 preparation and aren’t defined as the silica-based horn preparation.