Peculiarities of growth and development of alfalfa-grasses mixtures depending on species composition and fertilizing

The results of research on the influence of grass species composition, fertilizer level, and Fumar growth stimulator on plant density and botanical composition are presented. The experimental part of the work was performed in the scientific laboratories of the Department of Forage Production, Land Reclamation and Meteorology in the production unit of the National University of Life and Environmental Sciences of Ukraine "Agronomic Research Station". The territory of the research station is located in the Right-Bank Forest-Steppe and is a part of Bila Tserkva agro-soil district. The experimental plots were laid on typical low-humus chernozems, coarse-grained light loam in terms of mechanical composition, which are characterized by a high content of gross and mobile forms of nutrients. The climate of the region is characterized by unstable humidity and moderate temperatures. The average annual air temperature is 6-8 ° C. The annual amount of precipitation reaches 562 mm, during the growing season - 354-394 mm (63-70% of the annual norm), which fall unevenly throughout the year. Based on the research, it was found that sown grasses was formed with a density of 686–1250 shoots per 1 m2 and a height of 58–148 cm. Alfalfa-grasses and grasses are denser than alfalfa. During the period from the 1st to the 3rd year of grassland use, the density of alfalfa shoots decreases, while orchard grass and smooth brome grass increase, moreover, and more significant on the backgrounds of N60 application. During the first three years of use, grasslands are formed with the dominance of sown components with the share of alfalfa in single-species sowing 85–98%, in alfalfa-grasses mixtures - 30–58%. During the period from the 1st to the 3rd year of alfalfa-grasses stands using, the share of alfalfa decreases by 11–24%, and more significantly on backgrounds with N60 application. Also between the two kinds of grass components, there is a change of co-dominant - from meadow fescue to reed fescue, reed fescue to orchard grass, English bluegrass to smooth brome grass, while, as in grasses, reed fescue to smooth brome grass. English bluegrass in the 3rd year of use is much liquefied, reducing the share of participation to 5-14%.