The main tasks of this research are an extended analysis of the technological rut formation process’s geometric, force, and energy characteristics as a result of repeated passage of a forest machine on the soil surface. Existing experimental studies of the rutting process are associated with significant material costs and disruption of the forest ecosystem. The purpose of this study is to obtain similar experimental data in laboratory conditions, as well as establishing the correspondence of these experimental results to the results of field studies. The experiments were carried out on the specialized “soil channel” stand of Technical University in Zvolen (Slovakia), as well as in natural conditions in Brody Forestry of the Lviv Region (Ukraine). Geometric track characteristics were determined by length gauges. Power and energy characteristics of the track development process were determined using dynamometers, ammeters, and voltmeters. The physical and mechanical characteristics of the soil with which the mover interacted were determined by a dynamic hardness tester, a penetrometer, and a moisture meter. The characteristics of rut development processes in natural and laboratory conditions are similar to each other. This makes it possible to carry out a wide range of studies of a wheel with soil on a specialized stand and save considerable money during the implementation of full-scale experiments. So, the process of track development can be analyzed with the help of the geometric, force, and energy characteristics of the “wheel-soil” system obtained on laboratory equipment.

The study analyzes the rut formation process, changes in the physical and mechanical characteristics of the soil, and the energy demand associated with movement of the driven pneumatic wheel during repeated passes on the same track in a laboratory soil channel stand. The tests were performed on a prepared silty loam at an average moisture of 30.64%. Three vertical wheel loads were investigated: 4.84 kN, 6.94 kN, and 8.75 kN without a brush mat, as well as a vertical load of 8.75 kN with a brush mat. After each pass, the average rut depth, its increment, and the average dynamic penetration resistance were determined. For tests without a brush mat, soil shear resistance, power, work performed per pass, and work per 1 m of path were additionally determined. It was established that the rut depth increased non-linearly. The greatest increment was formed during the initial passes, after which the deepening rate decreased. In the tests without a brush mat, the final rut depth showed a trend of increasing with load: 8.1 cm for 4.84 kN, 9.2 cm for 6.94 kN, and 9.9 cm for 8.75 kN. The brush mat was associated with lower accumulation intensity of the rut depth and lower average dynamic penetration resistance in the soil. The change in rut depth is described with sufficient accuracy by a regression model with R² = 0.9512–0.9761 and RMSE = 0.194–0.344 cm. Energy indicators showed that the first pass was the most energetically intense, and the calculated work characterizes the total work of the wheel movement, not just the work of rut formation. The results confirm nonlinear rut accumulation with the highest increment during initial passes, and the highest energy demand during the first pass. The fitted model provides an engineering tool for estimating permissible pass numbers, while the integrated geometric–mechanical–energy approach offers a more comprehensive basis for planning forestry traffic than conventional bare-soil compaction tests.

The purpose of research: to determine the influence of different methods of sowing on the formation of seed yield and the efficiency of sunflower cultivation in the soil and climatic conditions of Western Ukraine. Methods. Field research was conducted in the soil and climatic conditions of Western Ukraine. The experimental field was characterized by sod deep clayey sandy soils. Two methods of sunflower sowing were studied: traditional with a row spacing of 70 cm using a «Gaspardo Renata R MTR 8» precision seeding vacuum planter and narrow-row sowing with a row spacing of 12.5 cm – the «Gaspardo Corona 600» seeding complex. During the research, the structural elements of sunflower seed productivity and the efficiency of two methods of sowing were estimated. Results: According to the research results it was established that in the variant with traditional sowing the average number of seeds in the basket was greater. The same trend was also observed concerning basket size, seed weight, and productivity of one plant, which made it possible to form a sunflower seed yield of 1.67 t/ha, which is 0.14 t/ha (by 9.1%) more than in the plot with narrow-row sowing. Direct operational use of technical means for performing technological operations of soil preparation, fertilizer application, and seed sowing in traditional sowing amounts to UAH 2,541/ha and is higher by UAH 667/ha compared to costs in the narrow-row variant. However, due to the higher yield in the version of traditional sowing, a higher income from the sale of seed was obtained by 1890 hryvnias/ha. Therefore, the effectiveness of the applied technical and technological solutions on the plot with traditional sowing amounted to 1223 hryvnias/ha. Conclusions. The «Gaspardo Corona 600» sowing complex can perform narrow-row sowing of sunflower seeds with the specified sowing rate in the conditions of Western Ukraine. Although a slightly lower yield was obtained in the variant with narrow-row sowing, direct operating costs for pre-sowing soil cultivation and sowing are lower than for technical and technological solutions for implementing traditional wide-row sowing. The results of using the «Gaspardo Corona 600» sowing complex for sunflower sowing can be useful for farmers when deciding to buy a row drill and save the financial resources of farms. Keywords: sunflower, methods of sowing seeds, row seeder, sowing complex, productivity, efficiency.