Analysis of the agrophytocenoses infestation in the conditions of Saratov Zavolzhye

The article presents three-year results of studies of weed infestation in spring crops of stationary crop rotation on the territory of the UNPO “Povolzhye” located in the Engels district of the Saratov region. As part of the work, a survey of a seven-field crop rotation with an area of 28 hectares was carried out using the route-reconnaissance method. The abundance of weeds in crops was assessed by eye and estimated by a six-point Drude scale. A detailed soil characteristic is presented with a description of the granulometric and chemical composition, the lowest moisture capacity and the thickness of the humus horizon. In accordance with the data from the UNPO “Povolzhye” weather station, a detailed description of the weather conditions for the growing seasons of 2021-2023 in the Engels region is provided. In the study area, 25 weeds were detected, and not a single crop was identified in the crop rotation in which all types of weeds were detected. In crops of cultivated plants, a different number of species of weeds were identified: in crops of chickpeas - 17, in crops of durum wheat - 14, in crops of millet - 13, in crops of annual sunflower - 11, in crops of common barley - 10. At the same time Amaranthus retroflexus L., Fallopia convolvulus (L.) ?. L?ve, Chenopodium album L., Convolvulus arvensis L., Lactuca tatarica (L.) C.A. Mey were noted in all crops. To determine the level of relationship between the species composition of weeds in different crop rotation, the S?rensen coefficient was used: the value of this indicator varied from 0.77 (weeds in annual sunflower and millet crops) and 0.74 (weeds in annual sunflower crops and chickpeas crops) to 0.40 (weeds of chickpeas and common barley, durum wheat and common barley). Thus, using the example of weed infestation of agricultural crops as part of a seven-field crop rotation, possible directions for changes in the species composition of weeds, which are elements of the restoration and preservation of relationships between different species in the agrophytocenosis, have been identified.