T. Dinev1*, I. Gospodinov2, A. Stoyanova3, G. Beev1, D. Dermendzhieva4, D. Pavlov3
1Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Agricultural Institute, 6000 Stara Zagora, Bulgaria
3Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
4Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
(Manuscript received 8 January 2016; accepted for publication 29 February 2016)
Abstract. The purpose of this study is to determine the influence of nitrogen fertilization and irrigation on the total count of aerobic mesophilic microorganisms, moulds and yeasts in the soil. The experiment was conducted in three variants and samples were taken as follows: from irrigated and fertilized furrow; from irrigated non-fertilized furrow and from furrow without irrigation and fertilization. For determination of total number of mesophilic aerobic microorganisms, moulds and yeasts the samples were diluted and cultivated on medium sheets coated with culture medium according to the requirements of the microorganisms. Data analysis shows that fertilization has the strongest multiplication effect on the number of aerobic mesophilic microorganisms in soil (their number increases from 10.522 x 106 to 12.8 x 106 cfu/g), whereas the irrigation does not have any statistically significant impact. The multiplication of moulds and yeasts in this trial is stimulated mainly by the increased humidity. When irrigation is applied the number of moulds and yeasts increases from 1.158 x 105 to 1.407 x 105 cfu/g, while fertilization does not affect their quantity in a statistically significant way.