Complex analysis of maize (Zea mays) yielding capacity and content of nutritive substances in silage and green mass depending on the phase of crop development and sowings damage due to frost was realized in the conditions of the Republic of Belarus. Yielding capacity of green mass in the analyzed sowings of hybrid maize Beliz on sod-podzolic light loamy soils was 75,1 n/ha at the stage of grain formation. Insufficient amount of positive temperatures at the beginning of vegetation stage was compensated by means of favourable weather conditions for growth and development of maize in July-September. In proportion to maize crops maturity there was stated the appropriate lowering of green mass. Taking place frosts lowered moisture content in crops. Yielding capacity of maize top biomass after cold spell was from 45,7 up to 44,8 c/ha. For the obtaining of the optimal amount of nutritive elements in the conditions of Vitebsk region of Belarus it was proposed to realize crop harvesting at the stage of milky-wax ripeness. The best composition of nutritive elements in silage was at the stage of milky-wax ripeness

Japanese millet (Echinochloa frumentacea) growing and yielding capacity was estimated in single and mixed sowings cultivated on sod-podzolic light loamy soils in the conditions of the Republic of Belarus; as well as comparative evaluation of silage quality and determination of digestibility of nutrients. Field experiment with forage crops was realized in threefold replication in accordance with the following scheme: Japanese millet (100%); Japanese millet (70%) + vetch (Vicia) (30%); Japanese millet (70%) + lupine (Luoinus) (30%); Japanese millet (70%) + pea (Pisum) (30%); Japanese millet (70%) + soybean (Glycine max) (30%). Research results showed that mixed sowings of Japanese millet with bean cultures made it possible to obtain higher yields than single sowings on 5,9-15,6%. Silage made of Japanese millet with bean culture contained higher amount of crude protein on 2,73-3,98% in comparison with silage which was produces only from Japanese millet. Silage produced from Japanese millet mixture with high protein crops had high energy and protein value: 0,90-0,92 fodder units; 9,47-9,59 mJ of metabolic energy per 1 kg of dry matter and 102-103 g of digestible protein per 1 fodder unit

Studying of the comparative productivity of various species and varieties of perennial grasses for the selection of the most productive species and increasing of production capacity of well-balanced feeds with low prime cost was realized in the conditions of sod-podzolic loamy soils of Vitebsk region of the Republic of Belarus. In course of study there were analyzed the following grasses: meadow clover (Trifolium pratense); creeping trefoil (Trifolium repens); great trefoil (Medicago sativa); timothy grass (Phleum pratense); meadow fescue grass (Festuca pratensis); chewing fescue (Festuca rubra); cock's-foot (Dactylis glomerata); common ryegrass (Lolium perenne); meadow foxtail (Alopecurus pratensis); awnless brome (Bromus inermis Leyss), and hybrid of fescue grass and perennial ryegrass. Studying of soil and climatic conditions in the analyzed area showed that leguminous grasses had higher yielding capacity than the cereal ones. After the 4-year observation the studied leguminous grasses provided higher yielding indexes in comparison with the cereal ones per 1 gram: dry matter – on 14,9%; available energy - on 29,7%; crude protein – on 44,7%. For the production of green mass in the conditions of Vitebsk region into the basis of planning of green and raw materials conveyor system there should be taken into consideration terms of beginning of hay cutting ripening of perennial leguminous and bluegrass grasses. Cereal grasses showed higher indexes of sugar content in 1,8 times in comparison with leguminous ones. For the provision of standard content of sugars and digestible protein in energy fodder unit it was reasonable to form grass mixtures on the basis leguminous and bluegrass grasses in ratio 60% and 40% respectively