The distribution of microorganisms in different types of agricultural soils in the Vojvodina Province

The soil fertility is determined by its composition and properties. Soil properties have a strong impact on a range of processes influencing crop yield, including microbial diversity. The distribution of microorganisms in soil is influenced by numerous abiotic and biotic factors, primarily by soil type, plant species, soil usage and tillage, use of organic and mineral fertilizers, irrigation, pesticide application, etc. Therephore, the objective of this study was to examine the distribution of microorganisms in different types of agricultural soils in the Vojvodina Province. The distribution of soil microbes was assessed on the basis of indirect dilution method on appropriate nutritive media. The total number of microorganisms was determined on soil agar, the number of azotobacters on nitrogen-free medium using „fertile drops“ method, ammonifiers on mesopepton agar – MPA, N-fixing bacteria on Fiodor medium, actinomycetes on synthetic medium and fungi on Czapek-Dox agar. Incubation temperature was 28°C, while incubation time depended on the tested group of microorganisms. All investigated microbial groups were found in all locations. Number of the microorganisms was uneven by type of soil. Studies have shown that the highest total number of bacteria was obtained on humogley and chernozem, in the locations of Bečej, Begejci and Kula. The highest distribution was recorded on chernozem, at the locations where the plough-field and harvest residues of maize were found, as well as on fluvisol and humogley. The highest number of ammonium-fixing bacteria was recorded in Zrenjanin, on chernozem. N-fixing bacteria were the most abundant on cambisol, in the locations of Petrovaradin and Vršac, as well as on chernozem, in the locations of Crna Bara, Orlovat, Popinci and Kula. The results showed that the highest number of actinomycetes was obtained in Žednik, on chernozem. The highest number of fungi was observed in Petrovaradin and Vršac, on cambisol. On average, abundance of the most studied microbial groups was the lowest in arenosol, solonchak, solonetz and pseudogley, while the highest distribution was obtained in chernozem, humogley, cambisol and fluvisol