Abstract
Pre-sowing soil tillage under irrigated agriculture conditions is characterized by high energy intensity and significant mechanical impact on the soil structure of the southern region. The soil cover of Southern Kazakhstan is predominantly represented by dark chestnut, chestnut, as well as brown and grey brown soils located south of the chestnut zone and occupying about 120 million hectares (44 % of the republic’s territory). The low humus content (1.0–2.0 %) determines their weak structure and increased sensitivity to intensive mechanical treatment; therefore, efficient farming in this zone is mainly possible under irrigation and the use of resource-saving technologies. The paper presents the results of engineering optimization and experimental studies of a rotary unit designed to simultaneously perform pre-sowing soil tillage and seed sowing in a single technological pass. The study includes analytical modeling of the interaction between working bodies and soil, optimization of geometric parameters of rotary blades, and comparative field tests of an experimental prototype (FS-2.1). A rational blade installation angle of 54–56° has been established, ensuring a reduction in the specific cutting area by approximately 22 % and a decrease in soil resistance to tillage. Field tests demonstrated the formation of a high-quality seedbed: the content of aggregates smaller than 25 mm reached 85.2 %, while the deviation in surface leveling did not exceed 5 mm. Compared with the conventional multi-pass technology, reductions in draft resistance, fuel consumption, and total energy costs by 38 %, 43 %, and 54.5 %, respectively, were recorded. The obtained results confirm that optimization of the parameters of rotary working bodies and the integration of tillage and sowing operations ensure improved energy efficiency of the technological process without deterioration of agrotechnical indicators.