The results of the analysis of yield and biological efficiency of single-species and mixed crops of cereals and legumes, depending on the cultivation zones, are presented. The study was carried out in the forest-steppe and steppe zones of Western Siberia and the forest-steppe zone of Eastern Siberia. The results were analyzed by means of Land Equivalent Ratio and the coefficient of aggressiveness. In the forest-steppe zone of Western Siberia, two-component mixtures with a seeding rate of 60– 75% of cereals (barley or oats) and 35–50% of legumes (peas) had an advantage in cultivation for fodder grain. The yield was 2.3–2.9 t/ha of grain with digestible protein content of 106–110 g per feed unit and the efficiency of the area use of 1.17 units. Peas mixed with wheat had the highest coefficient of aggressiveness (plus 0.53). In the conditions of the steppe zone of Western Siberia, two-component mixtures of barley and wheat with field peas are the most effective with a ratio of cereal and legume components of 60/50% of the total seeding rate of crops. The yield of these cenoses was noted at the level of single-species crops, and the nutritional value was 6–10% higher. Land Equivalent Ratio for this zone amounted to 1.21-1.3 units. The share of the legume component in the grain yield of three-component mixtures under unfavorable dry conditions of the steppe zone was registered insignificant. The value of the coefficient of aggressiveness of the legume component decreased to minus 1.58 and its share in the agrocenosis decreased to the utmost extent. The foreststeppe zone of Eastern Siberia is characterized by sufficient moisture, which contributed to a good grain harvest. The highest yield was provided by a mixture of oats with peas (4.85 t/ha) and oats with peas and barley (4.29 t/ha), with the Land Equivalent Ratio of up to 1.45 units and the coefficient of aggressiveness close to zero. In this zone, there are favorable growth conditions for binary crops.
