No abstract

Field experiments (2001–2005) were carried out to create optimal schemes for sowing mixtures of perennial grasses in the forest-steppe of Western Siberia. Objects of research were Krasnoobsky oats, Eastern galega Gorno-Altayskaya 87, awnless brome Antey. The soil of the plots was medium thick, medium loamy leached chernozem. The experiment was carried out in two layouts spread in time and in space. Grasses were sown under the cover of Krasnoobsky oats. Awnless brome was sown across galega in the first ten days of May. Seeding rate of awnless brome was 3.0; 4.5 and 6.0 million germinating seeds per hectare. Recordings of yield were made according to standard methods. The highest yield of galega dry mass was achieved when it was sown in rows with awnless brome planted with inter-row spacing of 15 cm (it was higher than with 30 cm inter-row spacing by 1.16 t/ ha and 0.63 t/ha, respectively). In the variant “three rows of galega + a row of awnless brome” (3 : 1), the yield of dry mass of the mixture in two cuttings was higher by 5.7 and 2.1% than when they were sown with every other row skipped. The total yield for two cuttings exceeded single-species crops of galega by 0.48–2.03, and awnless brome by 2.15–2.54 t/ha. A tendency towards a decrease in the yield of dry mass in single-species crops of galega with an increase in row spacing was noted. In mixtures sown at the same time according to the 3 : 1 scheme, the yield of dry mass was 5.14 t/ha in the first mowing and 4.05 t/ha in the second. This is higher than in the mixture sown according to the scheme “a row of galega + a row of awnless brome” (1 : 1) by 2.2–7.6, or 2.2–13.1%. Awnless brome in mixtures is more competitive than galega. An increase in the seeding rate of awnless brome from 3.0 to 6.0 million germinating seeds/ha in the herbage of galega increased the yield by 0.9–1.37 t/ha. The yield of dry mass of mixtures sown at the same time was higher than mixtures with awnless brome planted between rows of galega with spacing of 15 cm by 2%, and with row spacing of 30 cm by 10%.

The results of yield analysis and biological efficiency of joint cultivation of festulolium and alfalfa with different methods of sowing and nitrogen fertilizers in the forest-steppe zone of Western Siberia are presented. The joint sowing of festulolium with alfalfa at different alternation of rows reduces the yield of green mass by 8.9-15.1% compared to the single-seeded festulolium sowing. Nitrogen application at a dose of 30 kg/ha significantly increased the yield of festulolium mixtures with alfalfa in the variants of inter-row sowing by 21.2% and in the variant of sowing by seed mixture by 20.2% due to the increase of shoots on festulolium plant by 11.1%, and the shoot weight - by 12.5-17.8%. An increase in nitrogen dose to 60 kg/ha significantly increased the yield of festulolium 16.13 t/ha green mass (74.1%) compared with unfertilized background due to an increase in the number of shoots on the plant by 26.6% and an increase in weight per shoot by 30.1%. There was a 21.0-30.2% decrease in the number of shoots of the cereal component in the mixtures and a 76.7-82.1% decrease in the number of shoots of the legume component. At the same time, the shoot mass of festulolium increased by 8.3-42.5%, while that of alfalfa decreased by 54.3-81.5%, indicating its depression. Land equivalent ratio (LER) is higher in the variants with the application of fertilizers. With no nitrogen use, the major share of the factor belongs to festulolium. With the application of small doses of nitrogen, the impact of the legume component increases through increased competitive ratio (CR). At the same time, a positive value of the coefficient of aggressivity (CA) was noted in the cereal component, which characterizes it as the dominant species.

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.