Yefremova H. Effects of Legume Grass Undersowing on the Meadow Land Productivity in the Northern Ukrainian Forest-Steppe

Subject of research - the process of species, ecological and biological structure and legume-grass phytocenoses productivity formation depending on undersowing terms in them of different legume component species. The purpose - to establish the regularities of species, ecological and biological structure and red clover-grass stand productive feature formation depending on repeated undersowing different species of legume grasses. The research methods are field, analytic, visual, statistical. There are established the regularties of species structure and productive meadow stand potential formation at various undersowing terms of legume grasses, their allelopathic effect on undersowed components of other species of the same plant group and inhibiting physiologically active matters are identified and on the basis of the manifestation of plant secretion action by different species, the best pairs of legumes for substitution at repeated undersowing in time are substantiated. The recommendations on the meadowlandsimprovemend by means of repeated undersowing legume components into them are worked out. They allow to prolond on years the participation of legumes in grass stands at a level 35-40 per cent, to get at 60-70 hkg/ha of feed units, 11-12% of crude protein and to save annually up to 125 kg/ha of mineral fertilizer nitrogen. The research results are introduced in 2004-2005 in the Poltava region over an area 115 ha. The branch - agriculture.