Comparative productivity of spring wheat in repeated seeding in the southern forest-steppe of Western Siberia

Studies were conducted to determine the productivity in repeated seeding of spring soft wheat medium early biotype in a long-term stationary grain-fallow rotation with crop rotation: fallow - wheat - wheat - wheat - barley. A comparative evaluation was done of the effectiveness of agricultural technologies, cultivation of spring wheat on fallow predecessor and repeated seeding with different intensity influence of tillage systems and means intensification. It was found that without the use of intensification means there is a clear pattern of grain yield reduction by removing wheat from the fallow predecessor from 2.17 to 1.11 t/ha or by 48.8 %. When using inte- grated chemization compared to the control one wheat productivity increases by 2.2 times (up to 3.39 t/ha), but in repeated seeding the wheat yields are lower than that of the fallow predecessor by 39.0 %. At complex appli- cation of chemicals and increasing the productivity of culture to 2.47 t/ha grain yield combined variant exceeds the minimal option by 0.47 t/ha (21.2 %). It was found that the dominant factors affecting the grain yield of spring wheat are: chemization means - 30.6 %; contribution of predecessor - 22.0 %; weather conditions -%; tillage systems - less than 10 %.