Eight vineyards in Pfaffenheim (P) and Turckheim (T) close to Colmar, France, forming four pairs of organic and conventional
vineyards, were analyzed for microbial biomass and activity indices in relation to important soil chemical properties (carbon,
nutrient elements, heavy metals) and also to differences between the bottom and top positions on the vineyard slope. The question
was whether the vineyard management affects especially the soil microbiological indices. Three locations were on limestone
(P-I, P-II, T-II), one on granite (T-I). The gravel content (>2mm) ranged from 9 to 47%. The management systems had no significant
main effect on the contents of organic C, total N, P, and S. The mean total contents of man-derived heavy metals decreased
in the order Cu (164μg g−1 soil) > Zn (100μg g−1 soil) > Pb (32μg g−1 soil). The contents of microbial biomass C varied between 320 and 1,000μg g−1 soil. The significantly highest content was found at location P-II, the significantly lowest at the moderately acidic location
T-I. The contents of microbial biomass N and adenosine triphosphate showed a similar trend. At location T-I, the fungal ergosterol-to-microbial
biomass C ratio and the metabolic quotient qCO2 were significantly highest, whereas the percentage of soil organic C present as microbial biomass C was lowest. Highest percentages
of soil organic C present as microbial biomass C and lowest qCO2 values were found in the organic in comparison with the conventional vineyards. None of the soil microbiological indices
was significantly affected by the position on the slope, but all were significantly affected by the management system. This
was mainly due to the highest index levels in the organic vineyard location P-II with the longest history in organic management.
The organic vineyards were managed according to the biodynamic regulations of the Demeter (Pfaffenheim) or Biodyvin (Turckheim) organizations.