Variable lucerne is a valuable perennial legume crop known for its high fodder productivity, elevated raw protein content (up to 24%), drought resistance, winter hardiness, extended utilisation period, and the ability to maintain soil fertility. This crop is cultivated in pure stands and grass mixtures with other legumes and grasses. In 2016, a new variety of variable lucerne, Victoria, was included in the State Register of Breeding Achievements and approved for use in the Volga-Vyatka, Ural, West Siberian, North-Western, Central Chernozem, East Siberian, and Middle Volga regions of the Russian Federation, with the FSBI «UFARC UB RAS» (Federal State Budgetary Institution "Ural Federal Agrarian Research Center Ural Branch of the Russian Academy of Sciences") as the originator. The research was conducted in 2019–2022 to study the fodder productivity and nutritional value of monocultural and polyculture agrophytocenosis with the Victoria variety of variable lucerne on derno-podzolic soils in the Udmurt Republic. It was found that variable lucerne made the main contribution to agrophytocenosis yield over three years, accounting for 56–87% in two-component grass mixtures and 44–69% in three-component ones. The prevalence of Festuca rubra and Festuca pratensis in mixed crops increased from 18–26% in the first year of use to 32–43% in the third year. The highest yield (7.3 t/ha) of dry matter was obtained from the grass mixture of variable lucerne and red fescue at a stem density of 727–951 pcs/m2, with variable lucerne accounting for 74–80% and red fescue for 11–21%. Among lucerne-grass agrophytocenoses, the mixtures with Festuca pratensis were the most productive, yielding 6.3–t/ha of dry matter. The feed value of the selected grass mixtures was high: in 1 kg of dry weight, there was 17.4–21.3% raw protein, 0.69–0.76 feed units, and 9.2–10.0 MJ of metabolisable energy.