Choosing the sowing date and the cover crop when planting grasses of awnless brome for fodder in the forest steppe conditions of Western Siberia

The paper presents the results of using new annual grasses and their mixtures as cover crops for sowing awnless brome in spring, summer and late summer in the forest-steppe conditions of Western Siberia. The purpose of the research is to expand the species composition of cover crops, to substantiate the expediency of their application and their influence on the crop capacity of awnless brome. It was established that the use of rape or its mixtures with oats and winter rye as a cover crop during the sowing date from July 10 to 20 decreases the weediness by 30-59% comparing to the spring sowing date and by 72-85% comparing to the summer sowing date. Yield of cover crops in this case is 10.45-26.05 t/ha of green mass. Survival rate of brome after harvesting was 84-97%, which is the maximum in the experiment. Dry mass yield of brome averaged 5.17-6.61 t/ha in 2007-2011 at the late summer sowing date, which is higher by 38.6-77.2% compared to the traditional spring sowing date. Summer sowing date of brome under cover of Sudan grass with rape and millet with rape is impractical because it leads to thinning of brome up to 73-98 pcs/m2 and further reduction of dry mass harvest to 3.25-3.48 t/ha. In terms of the fodder unit provision with digestible protein, the variants of late-summer sowing of the first and especially the second cutting are stand out, where the protein content reaches 120 g, which is 31 g or 34% higher than at the spring sowing date. Compared to the spring time, the additional harvest of fodder units was 4.2 t/ha (excess by 64%), digestible protein by 271 kg (by 46%), metabolizable energy by 62.5 GJ (by 68%).