EN
Three combinations of sludge originating from two purification plants (5 and 10 tons of sewage sludge per hectare), two Swedish (Gudrun and Tora) and two Polish (marked as A and B) willow cultivars were used in the experiment. The aim of detailed microbial tests was to evaluate the influence of the sewage sludge on changes in microflora composition in rhizosphere of selected willow cultivars. Three-year results revealed that only 10 t/ha of sewage sludge rate caused significant increase of population of microorganisms active in carbon, nitrogen and phosphorus transformations. The decrease of fungi and actinomycetes, as well as the increase of bacteria, vegetative and sporulating forms, proteolytic and cellulolytic bacteria populations, and activity of ammonification, nitrification and denitrification processes were recorded. The influence of sewage sludge in willow cultivar on composition of rhizosphere microflora was found. Some bacteria as well as some fungi disappear, instead other appear especially toxin-producing fungi.