Roseroot (Rhodiola rosea L.) is an important medicinal plant with well-documented adaptogenic activity. The decrease in its natural resources induces to undertake research on the introduction of this species into cultivation. The aim of the present work was to determine the effect of organic and mineral fertilization on increasing the biomass of underground parts of Rh. rosea and the level of biologically active compounds. Throughout the study period, the highest raw material yield was obtained after the application of the following doses of mineral fertilization: N – 60.0 kg·ha^-1, P – 35.2 kg·ha^-1, K – 83.0 kg·ha^-1, without manure. The use of manure caused a decrease in the average rhizome and root weight by more than 20%. Mineral fertilization application increased the average raw material yield by about 30–40% and allowed obtaining the highest weight of underground organs of the species in question already in the fourth year of cultivation. Furthermore, the present study demonstrates that mineral fertilization does not affect substantially the level of the individual groups of compounds in the raw material, but the use of manure may significantly reduce the content of phenylpropanoids. The level of active compounds is also influenced by crop age. Two-year-old plants were characterized by the highest content of phenylpropanoids as well as by the lowest content of phenylethanoids and phenolic acids. In the following years of cultivation, no statistically significant changes were observed in the level of the analysed groups of compounds.

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