Influence of postseeding agrotechnological techniques on the formation of the agrophytocenosis and yield of millet in forest-steppe of Western Siberia
The research, carried out in the southern forest-steppe zone of the Omsk Region on common chernozem, concerns the influence of postseeding agricultural techniques (harrowing, rolling and their combination) on the formation of the agrophytocenosis and yield of the millet variety Omskoe 16, sown using a sowing-machine SKP-2.1 “Omichka”. Features of the influence of postseeding agrotechnological techniques on the density of seedlings, formation of a productive plant stand, weediness of the agrophytocenosis and productivity of the crop have been established. In the control sample (without herbicides), the use of preemergent harrowing reduced the number of weeds by 26.2-33.3%, while against the background of herbicidal weeding out it was reduced only by 10.1-25.9%. Application of additional compacting with a crowfoot roller 3KKSh-6A after sowing of millet using a rolling device insignificantly reduced the number of weeds (by 4.8-13.0%). The combination of rolling and harrowing contributed to the greatest decrease in the number of weeds. In these options of postseeding operations (options 5-7) the number of weeds decreased to 56-81 pcs/m<sup>2</sup> or 35.7-55.6% if compared to the control background, to 24-38 pcs/m<sup>2</sup> (by 29.6-55.6%) in case of herbicidal weeding of crops. A radical technique in reducing weeds is the use of herbicidal weeding out with preparations from the Group 2.4-D. On average among all the options, the number of weeds in crops decreased from 90 to 41 pcs/m<sup>2</sup> or by 2.2 times. In addition, the remaining group of weeds was dominated by mint species. The most effective, low-cost agrotechnological technique after crops sowing with a seeding-machine SKP-2.1 was a combination of additional rolling and preemergent harrowing with a harrowere BZSS-1.0 with a grain increase of up to 0.34 t/ha (17%). Without additional rolling of the soil, it is advisable to carry out double preemergent harrowing, which ensures a reduction of crop weediness by 28.6% and an increase in yield by 0.28 t/ha (14%).