EN
The source material of the studies carried out at The Research Institute of Vegetable Crops were the results of three-year observations on plots’ infestation. The experiments were conducted in Skierniewice in carrot and onion grown in monoculture and in leek and celeriac cultivated with three methods: with cover crops residues cut and incorporated 10–12 cm deep with the soil; in mulch with desiccated cover crops residues cut and left on the soil surface and without cover crops. On the base of obtained results the species composition of weed communities and the abundance of individual species were determined and the assessment of biodiversity using diversity indexes: the Simpson’s dominance index (D), the Shannon-Wiener’s (H’) and Simpson’s (C) diversity index was evaluated. It was proved that crop species and cultivation system affected the diversity of weeds species composition.