%0 Journal Article %T Photosynthetic activity and agro-energy efficiency of growing perennial grasses under different modes of use of the grass stand %A Grebennikov, V.G. %A Shipilov, I.A. %A Khonina, O.V. %K hayfield and pasture use, perennial grasses, agrophytocenosis, photosynthetic activity, leaf surface, productivity, agro-energy efficiency. %J Agrarian Bulletin of the %D 2020 %N 198 %P 9 %I Ural State Agrarian University