Creation of long-term hay agrocenoses sus-tainable in productivity in the Tver Region conditions

The aim of the study is to investigate the productive longevity of hayfield-type forage agrocenoses in the conditions of drained lands of the Non-Chernozem zone for their wide and effective use in forage pro-duction. The study of agrocenoses was carried out in the conditions of the Gubino agrotesting ground of the All-Russian Research Institute of Plant Protection, located in the Kalinin District of the Tver Region (2018–2023) on 2 legume-cereal grass mixtures consisting of three components and including: 1 – red clover, variable alfalfa, meadow timothy and 2 – red clover, variable alfalfa, meadow fescue. In the first two years of using the grass stands, the dry matter yield of legume-cereal mixtures with timothy averaged 6.8–10.3 t/ha of mixtures and with fescue – 6.6–9.3 t/ha. At this time, the yield was formed due to the active growth of red clover and cereal components. In the third and fourth years of use, during the period when red clover partially falls out of the grass stand, alfalfa, which is distinguished by its longevity, actively par-ticipated in the formation of the dry mass yield of grasses, providing an average dry mass yield of 3.9–7.7 t/ha for a grass mixture with meadow timothy and 4.3–7.6 t/ha for one with meadow fescue. Over the years of use, legume grass mixtures with timothy were distinguished by a higher yield (6.1–8.7 t/ha) than legume-fescue mixtures (5.5–7.5 t/ha). On average, over five years of use, based on the sum of the yield of two cuttings, the responsiveness of grass mixtures with timothy to mineral fertilizers was 2.7 t/ha higher for timothy grass mixtures. At the same time, the increase in the yield of mixtures with fescue was no more than 2 t/ha. The most productive species compositions of complex legume-cereal grass mixtures identified as a result of research on drained lands ensure the productivity of forage lands with an increased yield of high-protein balanced feeds up to 10.3 t/ha of dry mass.