Species composition of weeds in various crop rotations of the Mari El Republic

The article presents the results of long-term experiments to determine the species composition of weed vegetation, the dynamics of weeds on crops in various crop rotations is established. In order to develop rational measures to control weeds, their species and quantitative composition were studied. The experiment was carried out on the field of the Mari Research Institute of Agricultural Sciences, a branch of the Federal State Budgetary Educational Institution of the North–East, founded in 1996 and 1998. The duration is four rotations of six–field crop rotations. The soil is sod–podzolic medium loamy. The purpose of the work is to determine the species composition of weeds in crop rotations, to identify the influence of crop rotations, to trace the dynamics of crop contamination. The share of juvenile weeds accounts for 26 species, perennial – 10. The minimum amount of weed vegetation was noted in the III fruit–bearing crop rotation (average over the years – 49.55 pcs/m²), the maximum – in the grassy (61.15 pcs/m²). According to factor B, in all years of research on juvenile weeds, the lowest