The long-term storage of vegetable crops and potatoes in storage, even with a small content of soil and plant impurities in the heap, does not ensure the preservation of the required quality indicators of marketable products. The lack of modern technological foundations for improving the design parameters of machines for harvesting vegetables and potatoes leads to the impossibility of eliminating the loss of root crops, their damage, as well as the high-quality process of cleaning from impurities. This circumstance is due to the fact that modern technologies and technical means of harvesting root crops and onions are not able to provide high-quality marketable products with minimal labor costs. In this regard, a modern separating system of the harvesting machine has been developed, which ensures the variation of technological parameters under changing conditions for the harvesting of root crops and onions. The experimental studies of the developed harvester with an experimental separating system made it possible to ensure the high-quality harvesting of potato and onion tubers with the following parameter values: a completeness of separation of more than 98% and a damage to products up to 1.7%, at a speed of movement of 1.7 m/s for the separating system; a completeness of separation of more than 98% and a product damage of up to 1.1% at a speed of up to 1.0 m/s for the harvester; and a separation completeness of more than 98% and a product damage of up to 1.4% at a commercial product extraction depth of 0.02 m. The results of comparative studies on the quality indicators of the machine for harvesting root crops in the harvesting of potato and onion tubers are presented, indicating the prevailing values of the quality indicators of work in the harvesting of potatoes, depending on the change in the regime indicators of the quality of work.

Existing potato harvesters cause damage to marketable products as a result of the interaction of potato tubers with each other, with working bodies and soil clods, given the wide variety of soil and climatic conditions in which the harvesting process takes place. In addition, under homogeneous soil and climatic conditions within the same accounting area, there is a large deviation from the average values of the main physical soil constants—moisture and hardness. Field studies were carried out to determine the fractional composition of soil clods, size-mass parameters, as well as their physical and mechanical properties with the identification of the greatest force for their destruction. The article presents a methodology for conducting research to assess the influence of working bodies on the magnitude of the force impact on potato tubers and soil clods during harvesting, a methodology for assessing the dynamic destruction of soil clods. The results of comparative studies of the force impact of the working bodies of modern potato harvesters, which affect the destruction of soil clods, causing damage to potato tubers as a result of their interaction with soil clods are presented.

The obtained results of experimental studies on the influence of the physical and mechanical properties of an elastoplastic material (clods of soil and potato tubers) on the factors of its destruction when interacting with an absolutely solid body (separating working body) established that an increase in the density of a soil clod leads to an increase in the effort expended on dynamic destruction, regardless of the size fraction. Within one fractional group, the increase in force from the minimum value necessary for the destruction of the soil clod in the density range from 1300 to 1700 kg/m³ is on average 56–67 N. However, there is a tendency to increase the effort to destroy the soil clod with an increase in the size fraction, including identical density, by 7–8 N, which is 4–5% of the initial value of the destruction force of a given density. The greatest destruction of soil clods is provided at a moisture content of 22–24%, which should be explained by the formation of the physical ripeness of the leached chernozem. In addition, a decrease in soil moisture leads to a more intense adhesion of soil particles to each other and, consequently, to an increase in the force on the soil clod to destroy it.