The influence of the systems of primary soil treatments on a productivity of links of a grain-tilled crop rotation with oil crops and winter wheat on leached chernozem of the Western Ciscaucasia

A grain productivity and productivity of rotation links with oil crops (sunflower, castor, soybean, winter and spring rapeseed) and winter wheat depending on a system of primary soil treatment (intensive, plowing on different depths, minimal and surface) were studied in four rotations of 10-fields grain-tilled crop rotation on leached chernozem in a stationary trial at VNIIMK in 1971-2012. The results of 40-year usage of the different systems of the primary soil treatment in conditions of moistening showed that the highest productivity of sunflower and castor seeds was reached when using intensive and soil treatment and plowing on the different depths in crop rotation, and using of minimal (with and without herbicides) and surface soil treatments caused a decreasing of sunflower yield on 0.04-0.13 t/ha, or 1.5-5.0%, and castor yield on 0.16-0.42 t/ha, or 14-38%. The substantial decreasing of the winter wheat yield was noted in a link sunflower - winter wheat from the forth rotation in variants with minimal and surface soil treatments (on 0.27-0.46 t/ha). In this link was recorded the sharp decreasing of the productivity of the link, especially in variants with minimal (without herbicides) and surface soil treatments: on 0.40 and 0.36 t of grain units per ha, respectively. The negative influence of the minimal treatments on yield of the winter wheat was the highest in the link with castor in the fourth rotation, and the highest productivity of this link was noted at the primary soil treatment under the castor on depth 20-22 or 30-32 cm - 7.66 and 7.72 t of grain units per ha. The highest soybean yield (1.89 t/ha) was formed at the intensive soil treatment and plowing on the different depths. And at the surface ad minimal soil treatments it reduced on 0.07-0.27 t/ha, respectively. The substantial decrease of the winter wheat yield (on 0.42-0.45 t/ha) in a link with soybean was recorded in the fourth rotation at the minimal and surface soil treatments. The productivity of a link soybean - winter wheat lowered sharply in variant with the surface and minimal without herbicides soil treatments - on 0.40 and 0.53 t of grain units per ha, respectively. The most effective soil treatment under the winter and spring rapeseed is the intensive treatment (moldboard), and in the optimal years on moistening (2009 - for winter rapeseed and 2009 and 2011 - for spring rapeseed), along with the intensive one, minimal treatment (shallow plowing and moldboard). The highest yield of the winter wheat (5.23-6.70 t/ha) and productivity of a link of rotation with winter rapeseed (10.11 t of grain units per ha) were obtained at the intensive soil treatment. The highest yield of the winter wheat (4.68 t/ha) and productivity of a crop rotation link with spring rapeseed (6.78 t of grain units per ha) were obtained also at the intensive soil treatment. The studied links of crop rotation with oil and grain crops in the specific soil and climate environments showed the highest productivity at cultivation of the oil crops at moldboard on a depth 20-22 or 30-32 cm. the sharp reduction of yields of the separate crops and productivity of the rotation links were observed at minimal, shallow, and surface treatments in the fourth rotation. The application of such treatments without herbicides is the most dangerous.