In the year 2000 the occurrence of Azotobacter spp. in 31 Polish soils was examined and results of this study were compared with those published by Ziemięcka for 28 soils analysed in 1917-18. Almost 52% of the soils tested in 2000 were colonised by Azotobacter spp. indicating that intensification of agricultural practices that took place during the past century has not significantly changed (50% soils with Azotobacter examined in 1917-18) the colonisation of Polish soils by the studied bacteria. When present, numbers of these bacteria varied widely, from several (soils No. 17 and 31) to almost 10,000 cfu g⁻¹ of the soil No. 25.
A pot experiment was carried out to study the effect of adenine applied at following rates: Q, 1,10 and 100 mg per 1 kg of typical brown soil on yield and chemical composition of carrot and on numbers of soil microorganisms as well as on activity of soil enzymes. Experiment was done in two series: with or without Azotobacter sp. inoculation. The favourable effect of applied adenine together with Azotobacter sp. on yield of carrot roots was observed. Adenine increased nitrogen and potassium uptake by carrot but adversely affected number of oligotrophic, macrotrophic, fixing of mineral nitrogen bacteria, ammonifers, Azotobacter sp. and actinomycetes. The inhibition action of this preparation on soil dehydrogenases, urease, and basic phosphatase and stimulation action on acid phosphatase have been found.
W prezentowanym tekście przedstawiono aktualne informacje z zakresu technologii Efektywnych Mikroorganizmów. Zaprezen¬towano kierunki stosowania i rozwoju mikroorganizmów w Polsce i na świecie. Starano się przedstawić fakty świadczące o ich wszechstronnym i pozytywnym oddziaływaniu w wielu dziedzinach życia oraz środowiska nas otaczającego.