The paper presents the results of research into the technology of soft spring wheat cultivation of the Siberian Alliance variety taking into account the formation of the production process. The experiment was carried out in 2015–2019 in the zone of the northern forest-steppe of Kuznetsk Depression.  The  work  was  done  in  a  long-term  stationary  experiment  of  grain-fallow  crop rotation: fallow (bare, green-manured – rapeseed, melilot) – wheat – peas – barley (pure barley and intercropped with melilot). The following soil tillage systems were studied: deep moldboard (control), deep combined, minimum combined, minimum moldboard. The soil of the experimental plot was characterized as leached medium-textured, medium humus, heavy-loam chernozem. It was revealed that the influence of the preceding crop on the production process of soft spring wheat accounted for 80.4%, the effect of the soil cultivation system was 13.8%. The maximum yield in the experiment was obtained with minimum moldboard system of soil cultivation preceded by rapeseed green-manured fallow (3.34 t/ha) with the lowest cost of grain (4.6 thousand rubles/t) and high profit (30.3 thousand rubles/ha), control indicators being 3.26 t/ha, 9.2 thousand rubles/t and 15.2 thousand rubles/ha, respectively. The following positive effects on the formation of the production process were identified: soil moisture availability, microbiological activity, a decrease in phytosanitary tension, lack of soil compaction at a high content of agronomically valuable particles. Sowing rapeseed on green-manured fallow in the current crop rotation with the application of minimum moldboard tillage system is the most effective method of cultivating soft spring wheat of the Siberian Alliance variety in the northern forest-steppe of Kuznetsk Depression.

The paper presents the results of research (2015– 2018) into the main factors affecting efficiency of agrocenosis of spring common wheat, cultivar Siberian Alliance, with various systems of soil tillage and renewable bio-resources in a grain-fallow rotation. The research was conducted in the northern forest-steppe of Kuznetsk Depression in a threecourse grain-fallow crop rotation (fallow-wheatpeas-barley, barley intercropped with melilot) in a long-term stationary experiment. Various soil tillage systems were applied (deep moldboard, deep combined, minimum combined, minimum moldboard) preceded by bare fallow and green-manured fallow with rape and melilot. The soil of the experimental plot was leached chernozem. Crops of spring common wheat were sown with all types of soil tillage systems by the tillage and sowing machine Tom’5.1. It was revealed that the main factor influencing the yield of spring common wheat is water availability in the planting periods – full tillering, (r = 0.9579), beginning of earring – yellow ripeness, (r = 0.9611; R = 0.9500). A positive effect on wheat productivity was made by cellulosolytic activity and soil structure. The direct correlation between these factors and the crop yield was established, r = 0.6366 – 0.7298 and r = 0.6343 – 0.7103 respectively. A negative effect on the yield of wheat was made by the development of root decay (Bipolaris sorokiniana (Sacc.) Shoem), (r = – 0.4808). It was established that alongside the above-mentioned fac tors, the significant effect on productivity of spring common wheat was made by the systems of soil tillage (72.4%,) and the predecessor (22.0 %). The optimum conditions in agrocenosis of spring common wheat for formation of its yield during the years of research proved to be created by green-manured fallow (with rape) with minimum moldboard and deep moldboard soil tillage (2.72 and 2.78 t/ha respectively), which is 0.55 and 0.51 t/ha higher compared to analogous soil tillage systems preceded by bare fallow – control. Minimum moldboard soil tillage has an economic advantage over others with profitability of 193.6% and production cost at 5,000 rubles per 1 ton of grain.

The results of research on the dependence of agrochemical and agrophysical properties of leached chernozem on the system of soil treatment are presented. The work was performed in 2015–2019 in a long-term stationary field experiment in crops of spring soft wheat Siberian Alliance. The soil of the experimental site is medium-powered medium-humus heavy-loamy leached chernozem. Wheat was preceded by clean fallow, green fallow (rape), green fallow (cloverleaf). The following tillage systems were studied: deep moldboard (control), deep combined, minimum combined, minimum moldboard. There is an advantage in nitrate nitrogen content in the soil before sowing, in the phase of tillering and earing of wheat on the preceding cereal fallow (rape) when using the minimum tillage system (in autumn the break crop BDT-3 is planted). The effect of the tillage system on the nitrate nitrogen content in the soil in the phase of bushing of wheat - 15,5%, conditions of the year - 12,9, the interaction of these factors - 20,1% was determined. A positive relationship between the content of nitrate nitrogen in the soil and the amount of mobile phosphorus on the precursor green fallow (rape), r = 0.7118-0.8917 (R = 0.9500), was detected. High P2O5 content (from 150 mg/kg and above) was recorded on average for 5 years during the earing phase of wheat - 145.0 to 165.6 mg/kg. Maximum P2O5 values were detected for green fallow (rape) under minimum combined and minimum moldboard systems. A significant increase in exchangeable potassium content over the control average for 2015-2019 was observed with the deep combined tillage system - 5.0 mg/kg (NSR05). With the other tillage systems studied, the figures were at the control level. Higher soil pedality coefficients were revealed with a deep moldboard processing system (control) - 2.54, a minimum combined - 2.47, a minimum moldboard - 2.23 according to the predecessor green fallow (rapeseed); for green fallow (melilot) - 2.98 (deep moldboard). With an increase in the pedality coefficient, there was a decrease in the soil bulk density index, r = -0.3499 (R = 0.5760). A tendency was revealed towards a decrease in the soil bulk density to 0.98 g/cm3 according to the predecessor green fallow (rapeseed) with minimization of soil cultivation: combined moldboard and minimum moldboard; with a deep moldboard (control) - 1.02 g / cm3. As a result of the correlation analysis, it was found that with an increase in the soil bulk density, the content of P2O5, r = –0.4898, K2O, r = –0.2530, decreases.

The paper presents the results of research into the effect of different soil tillage systems on soil density and structure. The research was conducted in a long-term stationary experiment on the crops of Nikita spring barley. The soil of the experimental plot is classifi ed as leached, mediumtextured, medium-humus, heavy-loam chernozem. The following soil tillage systems with peas as a forecrop were studied: deep moldboard, deep combined, minimum combined and zero. The years of research (2015-2018) differed in heat availability and amount of precipitation. This allowed to study and carry out comparative assessment of the effect of various soil tillage systems of leached chernozem on agrophysical properties of soil. Yearly weather conditions had no signifi cant effect on soil density with all the studied soil tillage systems in single and binary crops of spring barley, whereby the indicators varied from 1.87 to 6.72%. Compared to deep moldboard tillage (control), there was an increase in soil density with zero tillage in singlecrop sowings of spring barley by 6.2%, and in binary crops – by 9.4%. However, the indices were not beyond optimum values of 1.02-1.05 g/ cm3. The optimum equilibrium soil density for the main subtypes of chernozems is 1.0-1.25 g/cm3. Minimum combined soil tillage system resulted in the stable content of valuable structural soil units 0.25-10 mm both in single-crop and binary sowings of spring barley at 68.3% and 68.9%, and the coeffi cient of soil structural properties – 2.15 and 2.21 respectively. It was established that the effect of soil tillage system on the creation of valuable structural units in soil was 21.4%, yearly weather conditions – 11.8%, type of crops – 25.5%.

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