AGROTECHNICAL JUSTIFICATION FOR INCREASING THE SPEED OF MOVEMENT OF CIRCULAR IRRIGATION MACHINES TO ACHIEVE A TRANSITION TO LOW‑RATE IRRIGATION

This study substantiates engineering solutions for increasing the travel speed of a center-pivot irrigation system to enable irrigation with low application depths (50–100 m³/ha). The proposed approach is based on the analysis of long-term experimental studies and current data on the condition of the irrigation and land reclamation sector in the Russian Federation. Materials and Methods. The study employed theoretical analysis of the energy consumption associated with the movement of the center-pivot drive towers, synthesis of field test results for upgraded sprinkler heads and deflector nozzles, statistical analysis of crop yield data obtained under different soil and climatic conditions, and an assessment of the current state of the irrigation equipment fleet. Results. The results demonstrate that doubling the travel speed of the center-pivot irrigation system from 1.8 to 3.6–4.0 m/min reduces the minimum irrigation application depth to 50–100 m³/ha. Replacing the conventional geared reducer in the drive mechanism with an orbital toothless gearbox increases transmission efficiency from 0.47 to 0.85–0.92 while reducing the drive weight by approximately fourteen times. The use of upgraded sprinkler heads and deflector nozzles increases the runoff threshold application depth by 20–30% and decreases water losses caused by evaporation and wind drift by 16–30%. Conclusions. Comprehensive modernization of center-pivot irrigation systems, including increased travel speed and the application of an orbital toothless gearbox, provides the technical basis for low-depth irrigation, reduces energy consumption, saves 300–400 m³/ha of irrigation water, and increases crop yields by 8–10%. These improvements contribute to higher water-use efficiency and enhance the sustainability of irrigated agriculture under conditions of increasing water scarcity.