Mineral fertilizers as a governing factor of the regulation of the number of fungi in soil

Over 2003-2005 period, a study was performed on the effect of different rates of NPK fertilizer of formulation 8:16:24 + 3% MgO (N1 - 400 kg/ha; N2 - 600 kg/ha; N3 - 800 kg/ha; N4 - 1000 kg/ha) on development of the soil fungi. The trial was set up in the experimental plum orchard established by Fruit Research Institute in Cacak (Serbia), and the laboratory of Department of Microbiology at the Faculty of Agronomy in Cacak (Serbia). Unfertilized soil was used as the control soil. Each of the stated variants was carried out in three replications. The size of the basic plot was 68 square meter. The effect of the studied mineral fertilizer rates was determined three times over the growing season, the number of fungi being checked by the indirect dilution method on Chapek nutritive medium. The results of the study inferred that the application of mineral fertilizers brought about the decrease in the number of fungi. Of all studied variants, the one with the highest nitrogen rate (variant N4) exhibited the strongest effect. The influence of the fertilizer was the highest at the third sampling. Furthermore, the effect was the highest in season 2003.