Yield and Root Growth in a Long-Term trial with Biodynamic Preparations

Crop yields and root growth were studied in a 6-year trial comparing conventional, organic, and biodynamic methods of fertilization. Intense use of a set of biodynamic preparations, including a nettlecontaining compound preparation, was found to have a balancing effect on the yields of maize and winter wheat. This effect may have been caused by greater root growth and improved root health. Introduction: Biodynamic farmers use ‘preparations’ to improve soil and crop quality, including fermented herbs to inoculate manure and compost, and field sprays that are either made from cow manure and silica fermented in cow horns, or from special mixtures of cow manure with concentrated applications of herbs (‘compound preparations’) (Koepf et al. 1989). In several studies biodynamic preparations have had hormone-like effects on various crops (Stearn, 1976; Goldstein, 1979; Goldstein and Koepf, 1982; Fritz, et al., 1997) and they can increase root growth (Bachinger, 1996; Goldstein, 1986). In Germany the biodynamic sprays increased crop yields (cereals and vegetables) on years where yields were low (Raupp and Koenig, 1996). Very little research has been done on compound preparations. These materials are often utilized as compost ‘starters’ or as field sprays and various formulae exist for their production. Our objectives were to compare conventional, organic, and biodynamic systems of fertilization on the yields of crops, and to test a newly developed nettle-containing variant of the ‘compound preparation’ field spray commonly used in biodynamic management. Methodology: An experiment was carried out for 6 years near Elkhorn, Wisconsin in a precipitation zone of approximately 720 mm/annum, on a McHenry silt loam (alfisol) that had been in continuous, conventional maize production. In 1993 a crop of oats and alfalfa was harvested in a checkerboard, and test plots for conventional, organic, and biodynamic systems were set out in 1994 on uniform, equally yielding parcels of soil in a randomized, complete block design with 4 replications. Average soil characteristics for pH, % organic matter, available P and K were 6.9, 2.43%, 18.5 ppm, and 110 ppm, respectively. The biodynamic plots were partitioned into subplots and five different biodynamic treatments were compared, including a check without compound preparations, and treatments including four different compound preparations. Of all the treatments used in the study, root growth was examined on only four treatments (conventional, organic, the biodynamic check which did not receive compound preparations (BD), and the treatment that included the new nettle-containing biodynamic compound preparation (BD+)). Plots were approximately 4 m x 7 m in size for the organic and conventional and 4 m x 3.5 m for the biodynamic subplots. The biodynamic check treatment (BD) differed from the organic only by receiving biodynamic preparations according to normal practice (Koepf, et al., 1989). This entailed application of biodynamic herbal preparations to compost piles and application of horn manure and horn silica to soils and crops, respectively. The BD+ treatment was the same as the BD treatment except that it received two extra applications of a compound preparation field spray made from a fermented mix of cow manure, stinging nettle (Urtica dioica L.) and the biodynamic herbal preparations. The mixture consisted of 40 kg of fresh cow manure, 1% by weight of nettle and one set of biodynamic preparations (yarrow (Achillea millefolium L.), chamomile (Matricaria chamomilla L), stinging nettle (Urtica dioica L.), oak bark (Quercus robur L.), dandelion (Taraxacum officinale L.), and valerian 1