Cover crops productivity, nutritionality and efficiency in fodder crop rotations in the Western Siberian forest-steppe zone

Research presents the results of studies (2008-2019) on the effect of the following methods on the productivity and fodder dignity of oats used as a cover crop: fertilization, over-sowing of vetch (accompanying cover crop), over-sowing of vetch against the background of fertilizers on leached chernozem in the forest-steppe zone of Western Siberia. Leached chernozem - low-humus, medium loamy, with a low supply of 0-20 cm layer with nitrogen and phosphorus, high - with potassium. The size of the plot is 8.4 m wide, 30 m long, half of the plot is covered with mineral fertilizers, the variants are repeated 3 times, the spatial distribution of the plots is systematic. Observations, selection of plant samples for chemical analysis, and yield accounting were carried out in accordance with the requirements of the field experiment methodology. Agricultural technology in the experiment is as follows: the introduction of mineral fertilizers; moldboard autumn plowing to a depth; harrowing in 2 tracks, planning of plots; fertilization; pre-sowing cultivation; rolling before sowing; sowing; rolling after sowing; mowing cover crops with loading into a cart. It was found that the introduction of mineral fertilizers for crops of oats (cover culture of awnless rump) increased the collection of green and dry matter by 1.4 times, the collection of digestible protein by 1.6 times. Overseeding of the legume component (vetch to oats) under cover crops for awnless rump with alfalfa without fertilization increased the dry matter harvest relative to the control by 15 %, against the background of fertilization by 29 %, contributed to an increase in the collection of digestible protein by 1.7 and 2.0 times, respectively. The saturation of the feed unit with digestible protein in cover crops increased from 95 to 110 g with fertilization. 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 over-sowing of the sowing vetch require additional production costs, however, over-sowing of leguminous crops is 3 times cheaper than the application of mineral fertilizers. This gives grounds to recommend mixed crops of oats with vetch for production as a cover crop.