Biodynamic agriculture was founded by Rudolf Steiner in his agriculture course of eight lectures held at Koberwitz (now Kobierzyce, Poland) in 1924 (Course of eight agriculture lectures). It is a variety of organic farming that not only avoids synthetic fertilisers and pesticides but also applies natural fertilizer sprays proposed by Rudolf Steiner. After Steiner's death in 1925, the theory and practice of biodynamics was developed by Dr Ehrenfried Pfeiffer at the Goetheanum in Switzerland and he published his book Bio-Dynamic Farming and Gardening in 1938.