EFFECTS OF BIODYNAMIC PREPARATIONS ON SOIL, WINEGRAPE, AND COMPOST QUALITY ON A CALIFORNIA VINEYARD
Jennifer Rose Reeve
Biodynamic preparations were investigated for their effects in soil quality, winegrape
quality and the quality of grape pomace and manure compost in a seven year study (1996
to 2003) on a California vineyard. The biodynamic field sprays (500, 501 and barrel
compost) were not shown to have any effect on soil quality. Analyses of the winegrapes
showed the biodynamic treatment to have significantly higher tannins in 2002 and Brix in
2003. In addition, biodynamic winegrapes contained notably higher tannins, total
phenols and total anthocyanins in 2003. When earthworms were presented with
biodynamically sprayed or unsprayed soil, significantly more worms migrated to the
biodynamically sprayed soil.
Grape pomace and manure compost treated with biodynamic preparations 502 through
507 showed increased ammonium concentration, higher dehydrogenase activity and
increased growth response of wheat seedlings in 2002. Compost in 2003 developed a high
pH, lost substantial N, and supported less aerobic microbial activity. The biodynamic
preparations were not shown to have an effect during these adverse composting conditions.