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

Abstract

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—1; N2 — 600 kg ha—1; N3 — 800 kg ha—1; N4 — 1000 kg ha—1) on development of the soil fungi. The trial was set up in the experimental plum orchard established by Fruit Research Institute Čačak, and the laboratory of Department of Microbiology, Faculty of Agronomy Čačak 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 m2. 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 rarefaction 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 highest at the third sampling. Furthermore, the effect was highest in season 2003.