The effect of cover crops on the fungal and bacterial communities in the soil under carrot cultivation

The purpose of the study was to establish quantitative and qualitative composition of soil-borne microorganisms in the cultivation of carrot. The experiment considered rye, white mustard, buckwheat and sunflower as cover crops and three systems of cultivation. The population of bacteria and fungi having an antagonistic effect towards selected fungi pathogenic to carrot was determined. The greatest total population of bacteria as well as Bacillus spp. and Pseudomonas spp. was observed in the soil when rye was the cover crop. The greatest quantity of fungi was found in the control, a slightly smaller amount after using sunflower, buckwheat and white mustard. The system of tillage had no effect on the communities of the investigated microorganisms. Rye and white mustard had the most positive effect on the quantity of antagonistic Bacillus spp., Pseudomonas spp., Clonostachys spp., Myrothecium spp., Penicillium spp. and Trichoderma spp. Regardless of the tillage system, the smallest quantity of antagonistic microorganisms occurred in the conventional cultivation of carrot.