Agroecological testing of Russian alfalfa varieties under the Sakhalin Island conditions

The studies were conducted on meadow-sod-gley medium loam soil of the test plot belonging to the Sakhalin Research Institute of Agriculture (Branch of the Federal Research Center the N.I. Vavilov All-Russian Institute of Plant Genetic Resources) from 2021 through 2023. The research goal was agroecological testing of ten alfalfa varieties on the Sakhalin Island. The research objectives included the evaluation of alfalfa varieties advantages regarding yields and nutritional value, and alfalfa varieties selection providing the highest yields and quality of forage under the Sakhalin monsoon climate. The experimental design involved nine varieties of Medicago varia and one variety of Medicago falcata. The weather conditions were generally favorable for the domestic alfalfa varieties potential manifestation throughout the test period. On average over three years, the plant height advantage over the standard (+ 2,0-5,7%) was found in the varieties Nakhodka, Agniya VIK, Taisiya and Voronezhskaya 6; and regarding the leaf coverage - in the varieties Uralochka, Nakhodka and Sarga (+ 1.0-6.6% compared to the Demetra standard variety). The average second-year alfalfa herbage yield was 56.6 t ha, and dry matter weight - 12.5 t ha; and on the third year - 51.4 t ha and 11.5 t ha, respectively. Over four mowings of the second- and third-year grass, the largest herbage yields were obtained from the varieties Taisiya, Nakhodka, Sarga, Agniya VIK, Viktoriya and Uralochka that exceeded the Demetra standard variety by 8-22%; and regarding dry matter weight, the advantage was found in the same varieties (by 9-24%). The varieties Sarga, Nakhodka, Taisiya, Viktoriya, and Uralochka produced the largest yields of fodder units and digestible protein per hectare; the varieties Nakhodka, Taisiya, and Sarga - the maximum metabolizable energy yields per hectare.