The idea of weeds as an element supporting the biodiversity in agrocenosis led to this research whose aim was to evaluate the effect of selected agrotechnical factors, such as crop rotation, tillage method and the herbicides applied on species diversity of weed communities. The research was carried out on winter wheat and spring barley cultivated in 5 cereal crop rotations which differed in their regenerating plants selection and in tillage. The number of species at tillering and at full vegetation, Shannon diversity indicator (H) and Simpson’s domination index (C) were taken as agrophytocenosis species diversity parameters. The effect of crop rotation on the species diversity shows non-significant, especially over full vegetation, while subsoiling lowered the species diversity of weed community in both crops. The application of herbicides reduced the weed abundance but not the weed diversity.

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