Sudan grass in agrocoenoses – a reliable source of forages in Pre-Baikal area

Research was carried out in the fields of the Irkutsk Research Institute of Agriculture in the Pre-Baikal Region in 2017–2020 to study the agro-technological methods of cultivating Sudan grass in agrocenoses with high-protein crops in order to obtain highly productive fodder balanced in basic nutritional elements. The research objects studied under the experiment were: Sudan grass (Sorghum sudanense L.) – Priobskaya 97; field peas (Pisum arvense L.) or pelyushka – Evrika; vetch (Vicia sativa L.) – Lyuba; Rape (Brassica napus L.) – Fregat. It was found that the highest yield of green mass – 22.4 and 22.5 t/ha on average for 4 years was determined in Sudan-rapeseed mixtures with a seeding rate of rapeseed of 50 and 60 %. The productivity and quality indicators of grass mixtures were directly influenced by the types of crops and their ratio during sowing. High values of productivity were provided by Sudan-pea mixed crops. The agrocenosis Sudan grass 70 + field pea 60 % was the best supplying feed unit harvest 5.6 t/hа, crude and digestible protein – 1.17 and 0.76 t/hа. This variant exceeded a single-type crop of Sudan grass in the same indicators of productivity, respectively – 1.3. 0.46 and 0.17 t/hа, аnd the blends with vetch in equal ratios of components – 1.6, 0.38, 0.25 t/hа, and with rape, respectively – 0.9, 0.34, 0.22 t/hа. Sudan-pea cenosis also served as a dominant of providing 1 f. un. with crude and digestible protein – 209.1 and 135.9 g. The nutritional value of green mass was determined by such important indicators as crude protein, sugar, energy. The highest availability of these nutritional elements in fodder was determined in mixtures of Sudan grass with field pea, respectively, on the average – 34.1, 7.23 g and 2.7 МJ.