COVER CROPS OF FODDER CROP ROTATIONS PRODUCTIVITY, NUTRITIOUSNESS AND EFFI- CIENCY IN THE WESTERN SIBERIA FOREST-STEPPE ZONE
The purpose of research is to study the effect of mineral fertilizers and the overseeding of vetch to awnless brome on the yield of cover crops in crop rotations and the quality of fodder mass in the forest-steppe zone of Western Siberia. The studies were carried out in 2008-2019 on the experimental field of the Siberian Research Institute of Feeds of the Siberian Federal Research Center of the Russian Academy of Sciences, located in the central forest-steppe Priobsky agrolandscape region of the Novosibirsk Region. The leached chernozem is low-humus, medium loamy, with a low supply of nitrogen and phosphorus in the 0-20 cm layer, and a high supply of potassium. Plot size - width 8.4 m, length 30 m, mineral fertilizers are applied to half of the plot, the repetition of options is 3-fold, the spatial distribution of plots is systematic. The application of mineral fertilizers for oat crops (a cover crop of awnless brome) increased the collection of green and dry mass by 1.4 times, the collection of digestible protein - by 1.6 times. The overseeding of the legume component (vetch to oats) without fertilization increased the yield of dry mass of cover crops for awnless brome with alfalfa by 15 % relative to the control, against the background of fertilizers - by 29 %, contributed to an increase in the yield of digestible protein by 1.7 and 2.0 times respectively. The saturation of the feed unit with digestible protein of cover crops increased from 95 to 110 g with the application of fertilizers. In the mixed sowing of oats with vetch, it was 141 g, and against the background of fertilization - 143 g, which is 48.4-50.5 % higher than the control and corresponds to the zootechnical norm. The use of nitrogen and phosphorus fertilizers and the undersowing of common vetch require additional production costs, but the oversowing of seeds of legumes is 3 times cheaper than the application of mineral fertilizers. This gives grounds to recommend mixed crops of oats with vetch as a cover crop.