Soil microorganisms have a key role in creation and maintaining of soil fertility. Anthropogenic impact on the soil microorganisms is extremely powerful. The application of fertilizer represents the most significant one. Applying fertilizers increase biological productivity of agroecosystem and microbiological activity of soil, but, at the same time, they cause certain changes inside them through the influence on microorganisms. This research examines how microbioligical activity of soil is influenced by the quantity of applied N fertilizer and "ugar" or tillage and the connection between this given activity and the maize quality. The total number of microorganisms and the number of amino -autotrophs depend on a phenophase of a plant, "ugar" or tillage and the quantity of applied N fertilizer. Less quantity of applied N fertilizer affects the increase of a number of microorganisms and components of the maize income whereas higher concentration of applied N fertilizer has an inhibitory effect.
Ključne reči: soil, fertilizer, total number of microorganisms, number of amino-autotrophs, maize