Agrophysical indicators of black soil typical in agrocenose of winter wheat (Triticum vulgare) in the right bank Forest Steppe of Ukraine

Abstract

The article presents the results of scientific research on the influence of four systems of basic tillage such as shelf tillage (ploughing at 20–22 cm), shelfless (chisel-deep-ripper at 20–22 cm), shelf-less tillage shallow (disk harrow at 10–12 cm) and shelflesstillage surface (disk harrow at 6–8 cm), and five preceding crops — peas, soybeans, corn for silage, winter rape, sunflower on compaction density and general porosity of black soil typical for growing winter wheat in the right-bank forest-steppe of Ukraine. According to the results of the research carried out in the stationary field experiment of the LLC «Agrofirma Kolos» educational-scientific-innovative center of agricultural technologies», the soil density and its total porosity determined at the time of sowing winter wheat had optimal parameters for all studied systems of the main tillage and placement of winter wheat after various preceding crops. With an increase in the depth of the studied soil layer, an increase in the index of soil density and a decrease in its total porosity were noted, which is natural. Depending on the system of the main tillage, the soil density in the 0–10 cm soil layer during the sowing period varied from 1.11 to 1.14 g/cm3, with lower values in the version with shelf and non-shelf tillage for 20–22 cm. Analyzing the entire studied layer (0–30 cm) of the soil at the time of crop sowing, it should be noted that both shelf (plow) and shelf-less tillage (chiseldeep-ripper) had close indicators of soil density in the studied layers, the values of which increased from the top to the bottom. With systematic shallow tillage by 12–14 cm and surface tillage by 6–8 cm, the soil layer of 10–20 cm was most compacted, with tendencies towards loosening in the 20–30 cm layer. Among the preceding crops, the higher soil density in the variant with placement of winter wheat after corn on silage is 1.14 g/cm3. The porosity indicator of the upper 0–10 cm soil layer at the time of sowing varied from 57.1% for shelf-less shallow tillage to 58% in the option with shelf tillage at 20–22 cm. The studied predecessors provided parameters of total porosity at the level of 57.5–58.0% for lower indicators in the version with sunflower. The analysis of the investigated indicators during the recovery of vegetation and before harvesting showed an increase in the soil density and a decrease in the number of pores in the soil for all investigated systems of the main tillage and preceding crops. It should be noted that the shelf cultivation of the soil (plowing at 20–22 cm) provided the most optimal parameters of the soil density and porosity of the soil in its individual horizons and in the arable layer as a whole. Other systems of basic tillage, despite the optimal values of agrophysical indicators on average in the arable layer, worsened the physical condition of the soil compared to plowing. The optimal combination of options in the experiment can be considered the use as preceding crops of winter wheat, legumes and winter rape in a complex with chisel tillage of the soil at 20–22 cm. This made it possible to ensure optimal indicators of soil density and general porosity not only in the upper 0–10 cm its thickness, but also in deeper layers.