The response of alfalfa cultivars to mobile aluminum toxicity

Alfalfa (Medicago sativa L.) as a perennial forage grass is widely adapted to favorable environmental conditions with wide range of soils including acid soils. The productivity traits of alfalfa in the soil without and with 1.8–14.7 mgAl/kg concentration of mobile Al were investigated. The study site was conducted at the Vėžaičiai Branch of the Lithuanian Research Centre for Agriculture and Forestry, 55°70 N lat., 21°49 E long. The experiment featuring 19 cultivars was established on a Balthygleyic Dystric Retisol in 2018. In 2019 and 2020, the productivity traits were evaluated: spring regrowth, plant height before flowering, stem number, seed yield, and fresh and dry matter yield. The mobile Al negatively influenced productivity traits of alfalfa in 2019 and 2020. Several cultivars of alfalfa were distinguished by tolerance to mobile Al and will be used for further selection for breeding. In 2020, the cultivar Europe from France was distinguished by spring regrowth, number of stems and fresh matter yield in the soil with mobile Al. The cultivar Ludelis from France differed by spring regrowth and height before flowering time in the soil with mobile Al in 2019–2020. The cultivar Skriveru from Latvia was the most yielding by seed yield in the soil without and with mobile Al in 2019. The Lithuanian cultivar Antanė was yielding by dry matter yield in the soil with and without mobile Al in 2019. The cultivar Žydrūnė from Lithuania was yielding by fresh and dry matter yield in the soil with and without mobile Al in 2020. This study on acid soils with and without mobile Al concentrations has revealed the differences of productivity traits under different environmental conditions of experimental years. Results of this study are important not only for Lithuania but also for the other lands of Europe where Retisol are prevails.