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Modern agricultural production is often associated with application of agrochemicals. One of them is glyphosate, which has become one of the most widely used herbicides in weed control. However, the widespread use of glyphosate may influence the living organism’s activity. The aim of this paper was to estimate the soil microbial activity after glyphosate application. Glyphosate (Glifomark SG) was applied at the end of 2017 on two locations: Principovo polje, and Novi Travnik (Travnik municipality, Bosnia and Herzegovina), so that corn and raspberry residues can be removed. Soil sampling (0–10 and 10–30 cm) was conducted at the time of glyphosate application, also 15 and 45 days after application. On control soil glyphosate was not applied. Chemical soil analysis (pH, content of humus, available P and K) was performed using standard methodology, whilst microbial abundance (total number of bacteria, ammonification bacteria, fungi, actinomycetes and glyphosate-tolerant bacteria) was analyzed using agar plate method. The results of chemical soil analysis showed slightly acid to slightly alkaline pH value, moderate to high humus content, and low to high content of available P and K. In most of samples, bacterial number was reduced 15 days after glyphosate application, whilst at the end of experiment increase of bacterial abundance was recorded. Similar results were obtained for fungi. Rapid decrease of actinomycetes number was observed after application of glyphosate. Two bacterial strains (PP-23 and NT-11) were able to grow on mineral medium supplemented with glyphosate in concentrations of 1 and 2% (v/v), thus representing a promising candidates for bioremediation of soil contaminated with glyphosate.

When a pesticide gets into soil, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors such as physical, chemical, and biological characteristics of soil and climatic factors. Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on microbial populations and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity. The aim of this study was to analyze post nicosulfuron application dynamics of microbial populations’ activity in the soil. By standard methodology, soil pH value was determined as slightly acid to slightly alkaline, humus and available K content as moderate to high, and available P content as very low to moderate. Microbial abundance (total number of bacteria, number of ammonification bacteria, fungi and actinomycetes) was determined by agar plate method. The application of nicosulfuron in all samples and at both locations has resulted in increased number of bacteria, fungi and ammonification bacteria and reduction of the number of actinomycetes. The highest positive effect on the number of microorganisms was 15 days after treatment with nicosulfuron.