June 19, 2018 on the basis of the Federal State Budgetary Educational Institution of Higher Education "Russian State Agararian University - Moscow Agricultural Academy named after K.A. Timiryazev, in the dissertation council D 220.043.16, the defense of Valentina Valentinovna Osipova, deputy director for teaching and educational work, head. Department of Agronomy of the Oktyom branch of the Yakutsk State Agricultural Academy, on the dissertation for the degree of Doctor of Agricultural Sciences on the topic "Scientific substantiation of the technology of cultivation of alfalfa (Medicago L.) in adaptive agriculture of the Republic of Sakha (Yakutia)", which was carried out at the Department of Oktyom branch of FSBEI HE "Yakutsk State Agricultural Academy".
For the first time in the conditions of permafrost taiga pale-yellow and floodplain soils, the critical temperatures of freezing of alfalfa at the level of the root collar were determined for the studied varieties. Alfalfa varieties with high economic and biological indicators have been identified. For the first time, the agro-ecological foundations for the cultivation of sickle alfalfa (Medicago falcatа L.) and variable alfalfa (Medicago varia Mart.) Have been developed. In particular, for the permafrost floodplain soils of the Prilenskaya zone and permafrost taiga pale soils of the Privilyui zone: the optimal seeding rates, sowing dates, mowing times for forage mass, effective doses of mineral fertilizers when cultivated for fodder and seed productivity of alfalfa have been established; the influence of the seeding rates of alfalfa seeds and moisture supply of herbage on the number of weeds; patterns of development of the root system of alfalfa, depending on the methods of pre-sowing soil cultivation, methods of sowing and different doses of mineral fertilizers in different soil and climatic zones, as well as its chemical composition; dependence of the development of the leaf surface of alfalfa agrophytocenoses on mineral nutrition and soil and climatic conditions under different sowing methods; methods of rejuvenating herbage of crescent alfalfa, significantly increasing its productive longevity; the level of pollination of crescent alfalfa, depending on the cultivation technology in the Prilenskaya and Privilyui zones.
V.V. Osipova developed and implemented in the republic scientifically grounded recommendations on the technology of cultivation of sickle-shaped and variable alfalfa in the Privilyuisk and Prilensk soil and climatic zones of Yakutia.