AGROPHYTOCENOSES PRODUCTIVITY UNDER COCULTURING OF PERENNIAL GRASSES AND JERUSALEM ARTICHOKE

The productivity of legume-grass stands (with the participation of meadow timothy, boneless stalk, hybrid clover or variable alfalfa) and joint crops of the above-mentioned perennial grasses with jerusalem artichoke in the conditions of Karelia was evaluated. Inclusion of new ones for the Republic of Medicago varia Mart. and Helianthus tuberosus L. in the composition of agrophytocenoses with a long period of economic use will contribute to solving the problem of increasing the volume of harvesting and the quality of feed. It was found that in the first year of plant life, the highest indicators of productivity and quality of aboveground dry mass (5.9 t/ha and 6.5 thousand fodder units) were provided by single-species planting of jerusalem artichoke. In the second year of life, the growth rates of plants differed in mowing and depended on the heterogeneity of meteorological conditions, the biological characteristics of the species and the composition of the herbage. In the first mowing (June 25), when harvesting only perennial grasses, the differences in the biomass yield in the experimental variants relative to the clover-grain control were insignificant. In conditions of long daylight, the process of forming the leaf-stem mass of H. tuberosus continued until the second alienation of grasses (August 18). In total, for two mowing operations with strip joint cultivation of perennial grasses and jerusalem artichoke, the yield of dry forage mass increased almost twice relative to the single-species agrophytocenosis of H. tuberosus, while the maximum productivity per hectare (8.1 tons of dry mass, 8.46 thousand feed units, 95.58 GJ of exchange energy, 1.45 tons of crude protein) was obtained in the variant with the participation of hybrid clover.