EN
This paper presents the results of investigations on the weed infestation and vertical distribution of weed seed bank in rendzina under spring cereals cultivation in crop rotations and monoculture. Used herbicides (MCPA and fenoxaprop-P-etylu) decreased the number of weeds and species composition in comparison with harrowing. In the soil layer of 0-25 cm used in the monoculture there was found about 22,9% weed seeds more than in crop rotation. In the canopy of spring cereals the following weeds dominated: in crop rotation - Chenopodium album, Echinochloa crus-galli and Veronica persica; and in monoculture - Stellaria media, Galium aparine and Chenopodium album. In the soil layer of 0-25 cm used in crop rotation and monoculture the following weed seeds dominated : Amaranthus retroflexus, Chenopodium album and Stellaria media.