Microorganisms take part in soil formation and maintain soil fertility. The abundance of certain microbial groups and dehydrogenase activity are used as an indicator of general microbial activity and potential soil fertility. Soil microbial properties are influenced by environmental conditions, cultural practices, crop species grown and the presence of heavy metals. Each type of soil has its own microbiocenoses, but the method of soil tillage/use can affect microbial activity both positively and negatively, and it can have an indirect influence on the fertility of the soil as well. The aim of this investigation was to examine the effect of different methods of land use on the number and enzymatic activity of different groups of soil microorganisms in chernozem. All the microbial groups included in the study were detected in the soils taken from the locations studied. Their abundance and enzymatic activity depended on the method of land use and differed from the results obtained in 1992, relative to which there was an either upward or downward trend present.Brojnost pojedinih grupa mikroorganizama i aktivnost dehidrogenaze koriste se kao jedan od pokazatelja opšte mikrobiološke aktivnosti i potencijalne plodnosti zemljišta. Svaki tip zemljišta ima svoju karakterističnu mikrobiocenozu, a način obrade/korišćenja zemljišta može uticati pozitivno ili negativno na mikrobiološku aktivnost, što se neposredno odražava i na plodnost zemljišta. Cilj ovih istraživanja bio je ispitivanje uticaja različitog načina korišćenja, zemljišta tipa černozem, na zastupljenost ukupnog broja mikroorganizama, broja diazotrofa, amonifikatora, aktinomiceta i gljiva kao i aktivnost enzima dehidrogenaze. U poređenju sa rezultatima iz 1992. godine ukupan broj mikroorganizama, brojnost oligonitrofila, aktinomiceta i dehidrogenazna aktivnost imaju trend porasta. Zastupljenost Azotobacter-a i gljiva je manja, a brojnost amonifikatora se nije menjala
