Features of formation of density of perennial grasses grass stands and the evaluation of their efficiency in the application of joint and strip crops in conditions of the Baikal territory

The efficiency of perennial grasses: bromopsis-inermis, galegaorientalis, buniasorientalis, polygo-numdivaricatum cultivated in single-species, mixed, joint tape and crops has been found out. The main indicators of their growth and development, viabil- ity, survival, density of grasses in created agrophy- tocenosis (APC) are presented. Field viability of seeds of perennial grasses (F) in the conditions of the region was low (10-16 %). It is connected with fast spring siccation of soil cover, the deficiency of moisture at the depth of crops of perennial grasses (2-3 cm). Considerable part of sowed seeds (over 50 %) in the first year of life continued to ascend after summer rains. The most objective indicator of developing density of grasses in experimental crops is the accounting of field viability and survival (FVS). The density of perennial grasses depended on the influence of plants on each other and their regulation in experimental crops. The low indicator of FVS was characteristic for buniasorientalis (9.1-13.7 %) and polygonumdivaricatum (19.2-33.6 %) - in mixed crops; in joint and tape it raised by 1.5-2.0 times. In the second and third lives the indicator of FVS increased in all experimental grasses. In the first year of life perennial plants grew and devel-oped slowly, root system was formed, herbage height by the end of vegetation reached 20-25 cm. In joint and tape crops at placement of components through 60 cm interspecific competition decreased. The productivity of green material of perennial grasses of the second year of life in joint and tape crops was higher, than in single-species and mixed APC. At the increase in space occupied by test plants, they use all ecological conditions of growth more evenly, that is one of the reasons of increas-ing their efficiency. APC of bromopsisinermis with galegaorientalis and buniasorientalis had the high-est productivity of green material - 26.8 and 27.6 t/hectare.