INFLUENCE OF MINERAL AND ORGANIC N-FERTILIZERS ON SOIL MICROBIOLOGICAL PARAMETERS IN THE INTERNATIONAL ORGANIC NITROGEN LONG-TERM FERTILIZATION EXPERIMENT (IOSDV) IN BERLIN-DAHLEM

摘要

The influence of mineral and organic N-fertilizers on soil microbiological parameters was investigated on soil samples from the International Organic Nitrogen Long-Term Fertilization Experiment (IOSDV) in Berlin-Dahlem. Total six variants were compared and both quantitative and qualitative parameters of the microbial biomass was determined. The combination beet leaves-straw-green manure has shown significantly the highest content of C and N in the microbial biomass, the highest C_(mic)/C_(org) quotient and the highest dehydrogenase activity, but the metabolic quotient was the lowest. In contrast the variant farmyard manure has had to the most unfavorable microbiological conditions in soils. It was concluded, that the farmyard manure can replaced byother kinds of organic fertilizers (beet leaves-straw-green manure) in the IoSDV Berlin-Dahlem.