Selection and substantiation of cultivator adjustment parameters for differential soil treatment on potato based on the rheology state of soil horizons

The article presents results of theoretical studies on the determination rational parameters of placement tines on the frame interrow cultivator for differential tillage of potato field. Differential tillage means depth adjustments of tines according soil condition and their placement on the cultivator frame. The main goals of differential tillage by inter row cultivators are the elimination of soil compaction between ridges, formed by potato planters, as well as loosening of the zone of location of the potato tubers. Deep loosening after planting provides good conditions for the complete assimilation of water by soil after rain or irrigation, protects the top soil layer from erosion and also eliminates the over moistening in the autumn. Loosening the soil in the zone of the tuber placement ensures the obtaining of a fine-grained soil structure, which helps to create best conditions for the growth of plants and development their root system, as well as to ensure favorable conditions for soil separation during harvesting. The substantiation of rational parameters for tine placement on the frame of row cultivator was carried out on the base of the regularities of soil rheology, the heterogeneity of soil composition in different layers of arable and subsoil horizons, as well as the variability of their physic-mechanical properties. These regularities influence the development of deformation and cracked zones during the interaction ripper tines with the soil. As a result of the theoretical studies was developed a method for calculating the rational placement of ripper tines on the frame of the row cultivator for fulfil differential tillage on the potato based on the rheological state and heterogeneous structure of the soil horizons. Using of this method allow ensure high quality structure of tilled soil.