Influence of agro-landscape on the ecological sustainability of cover oats and perennial herbs phytocenoes

Biodiversity is the cornerstone of modern agro-phytocinology. Based on its records, the ecological sustainability of agricultural landscapes is predicted. The aim of the research was to study the influence of soils and the topography of the terminal moraine hill, as well as the age of phytocenoses, on the value of the coefficient of floristic similarity of oat communities with over-sowing of grasses (2019) and clover-and-timothy herbage of 1 year of use (2020). Monitoring of the botanical composition of phytocenoses was carried out on a transect – a field crossing slopes of different exposures and soils of varying degrees of swampiness, located at the agroecological station All-Russian Research Institute of Reclaimed Lands (VNIIMZ; Tver region, Russia). The standing density of oats, red clover, timothy grass, weed species, as well as other environmental parameters were taken into account on 30 systematically located land plots. It is shown that only a few plant species affect the Jaccard coefficient. The topography and soil features of the agricultural landscape, as well as the age of the plant community, have a significant impact on the stability and productivity of the agrocenosis. The main factor affecting the variability of the floristic similarity indicator is soil hydromorphism. An increase in the index of the floristic similarity coefficient is observed on all soils and slopes as the herbage matures. Productivity of grasses depends to the greatest extent on the nature of the interaction of the relief and soils – on the southern slope of the hill, a low hay yield was noted (on average, 5.34 t/ha), the minimum of which was observed on highly swampy soils (4.92 t/ha), on the northern slope, the yield of hay was higher (on average 6.57 t/ha), the minimum of which was noted on moderately swampy soils (6.26 t/ha). Based on the revealed patterns, it is possible to develop measures to adapt technologies for growing perennial grasses to the natural conditions of farms in the mode of adaptive landscape fodder production.