Influence of sowing techniques on dry matter yield of variable alfalfa in the Middle Cis-Urals region

The aim of the research is to study the influence of sowing methods (cover crop, sowing method) and the age of the grass stand (year of use) on the dry matter yield of Victoria alfalfa. The studies were conducted in 2019–2024 at the experimental field of the Udmurt Agricultural Research Institute — a branch of the Udmurt Federal Research Center of the Ural Branch of the Russian Academy of Sciences. The soil is sod-podzolic, medium loamy, with a neutral reaction (pH), low humus content, a very high content of available phosphorus, and a medium content of exchangeable potassium. The weather conditions during the growing season in the year of sowing the Victoria alfalfa variable were excessively humid (hydrothermal coefficient = 1.77), while during the years of using the forage grass stand they were arid (hydrothermal coefficient = 0.59–1.16). Over five years of using the grass stand, long-term productivity of alfalfa at a fairly high level was revealed: in the first and third years of use — 6.2–10.3 t/ha, in the fourth and fifth years of use — 3.8–6.5 t/ha of dry matter. An increase in the density of the forage grass stand was noted, from 592–644 plants/m² in the first year of use to 841–1009 plants/m² in the fifth year of use. The height of the grass stand was at the level of 49–56 cm under relatively favorable conditions, and 40–46 cm in dry years. The highest dry matter yield (7.3 t/ha) was obtained when sowing alfalfa without a cover crop using the conventional row method, with a grass stand density of 708 plants/m² and a height of 48 cm. In this treatment, forage with high quality indicators was obtained: crude protein content of 20.2%, metabolizable energy concentration of 9.20 MJ/kg, and feed unit value of 0.69.