EN
The study was conducted in 2006 – 2008 at the Production and Experimental Station of the University of Warmia and Mazury in Olsztyn, located in Bałcyny (NE Poland). The objective of this study was to determine the microbial quality of soil after Brassicaceae grown as forecrops for winter wheat. A field experiment was established on grey-brown podsolic soil, and it involved the following forecrops: winter rapeseed, spring rapeseed, white mustard, Chinese mustard, and winter wheat as control. Soil samples for microbiological analyses were collected in the spring, before the sowing of forecrops, and in the autumn, after the harvest of Brassicaceae and ploughing-in crop residues. Bacterial and fungal communities isolated from soil sown with Brassicaceae as forecrops were generally more abundant and diverse. These communities exerted an inhibitory effect on the growth of soil pathogens. Forecrops with the greatest microbiological potential were white mustard and winter rapeseed.