Nikolay Nikolaevich Lazarev, Vladimir Alexandrovich Tyulin and Evgenia Mikhailovna Kurenkova
Abstract
Eleven years of studying the productive longevity of the cultivars of variegated alfalfa and creeping alfalfa have shown that variegated alfalfa steadily remained in the grass stands for six years, providing the yield of 6.24 -9.25 tons of dry matter per hectare. In the eighth year of life, cultivars of variegated alfalfa thinned to 17- 32 plants per 1 m2, and in the tenth year - to 6- 9 plants per 1 m2. Creeping alfalfa in the first six years of the grass stand use provided the same yields as variegated alfalfa, but it proved to be more resistant to various types of withering. Until the eighth year, alfalfa cultivars had sufficient density (44 -49 plants per 1 m2) for ensuring the yield of dry matter at the level of 5.03 â 10.04 t/ha. By the tenth year, the density of the creeping alfalfa grass stand reduced to 17 -21 plants per 1 m2. In the eleventh year of life, the superiority of creeping alfalfa in terms of the yield was 19.5 %. On average over the entire period of grass stands use, creeping alfalfa surpassed variegated alfalfa in terms of productivity by 17.5 %. No significant differences were found between the cultivars within alfalfa species. Over the 11 years of use, the cultivar of variegated alfalfa ensured the dry weight yield of 5.42 to 5.48 t/ha, and the cultivar of creeping alfalfa - 6.45 to 6.70 t/ ha. Even on the ninth year of life, the share of creeping alfalfa in the botanic composition of the grass stands was 79.2 â 85.