Andjelković, SnežanaZornic, VladimirBabić, SnežanaMilenković, JasminaJevtić, GoranMarković, JordanBekčić, Filip2025-06-302025-06-30202097 8-99976-787-5-1https://rifoc.ikbks.com/handle/123456789/183М 33 Саопштење са међународног скупа штампано у целиниThe community structure and number of microorganisms are different in different soil types, and they represent the result of interactions between the soil type, plant species, localization of the microorganism in rhizosphere, anthropogenization and other factors. Certain microorganisms known for their ability to fix atmospheric nitrogen are also important for the development of healthy soil structure. Furthermore, they are important for the nitrogen input to soils in agroecosystem and represent economically attractive and ecologically acceptable means for reducing external inputs and improving soil quality. Soil samples were taken from pastures and meadows in the area of Stara Planina Mountain. According to its geographical and climatic conditions the area is characterized by typical hilly-mountainous regions with meadow and pasture systems for fodder production. The aim of this research was to examine quality of grasslands soil, so the parameters of soil fertility and number of free-living nitrogen-fixers from 55 locations were determined. The largest number of soil samples were characterized showed good amounts of soil organic matter, high nitrogen content and slightly acidic chemical reaction. Fjodorov agar was used for determining the number of free-living nitrogen-fixing microorganisms and their abundance ranged from 6.378 to 7.021 (log of number) per gram of absolutely dry soil.enCC0 1.0 Universalhttp://creativecommons.org/publicdomain/zero/1.0/free-living nitrogen-fixing microorganismssoilStara Planina Mountain.conferenceObject