In this book Manfred Klett provides a fascinating overview of the history of agriculture, then goes on to discuss the practicalities of spray and compost preparations, and the philosophy behind them.

This is essential reading for any biodynamic gardener or farmer who wants to understand the background to core biodynamic techniques. (Replaces the author's Biodynamic Spray Preparations.)

This is a Board favorite: "Helpful for understanding the preps and sprays." (Paula Manalo)