Biological features of formation of perennial binary grass crops

The paper deals with the impact of binary mixtures of perennial grasses on the productivity and quality of forage crops that differ in their species composition. The studies have shown that mixed crops exceeded single-species crops in all indicators of forage crops productivity. In total over five years binary crops of Poterium polygamum exceeded singlespecies ones in all productivity indicators. The plants safety by the end of vegetation was also slightly lower than in single-species crops, which can be explained by greater competition for light, moisture and nutrients. So the safety of Medicago sativa L. was 81.8%, Onobrýchis – 83.6%, Galéga orientális L – 89.7%, Poterium polygamum – 74.6%, which is lower than that of legumes in single-species crops. In all years of herbage use, the binary crops exceeded singlespecies ones. On average, for 5 years of research, the yield of Poterium polygamum was 25.5 t ha-1 , Medicago sativa L. – 22.5 t ha-1 , Onobrýchis – 23.7 t ha-1 . Among legumes, the maximum yield had Galéga orientális L agrocenosis – 26.1 t ha-1 . Mixed crops of burnet with leguminous grasses were characterized for yielding the vegetative mass on average 28.5–30.9 t ha-1 . Maximum values of binary Poterium polygamum crops characterized crops with the leguminous plant component of goat’s rue in all years of research. Mixed crops also showed maximum values of dry matter per unit area and amounted respectively 33.52–36.74 t ha-1 . The same pattern continued in the yield of fodder units, digestible protein and metabolic energy, their maximum was obtained at the variant Poterium polygamum+ Galéga orientális L.