The objective of this study is to analyse the possibility of using the dry-air ultrasonic method of presowing treatment of barley seeds in the agricultural industry and to develop semi-industrial equipment for technology implementation. In the case of dry-air ultrasonic treatment, there is no environmental contamination by harmful substances and there is a possibility of using the remains of seed grain as raw materials for producing foodstuffs or feedstuffs, since the nutritional qualities of seeds do not decrease at all as a result of the effect of ultrasound. As a result of calculations by the finite element method, sections with a disk radiator for dry-air ultrasonic treatment of barley seeds were developed that made it possible to assemble waveguide systems by adding sections without changing the resonance frequency of the entire system. It was found that the ultrasonic treatment of barley grains can cause both suppression and stimulation of their vitality. High-intensity ultrasonic treatment can inhibit the growth of plants. The modes of ultrasonic treatment have been determined that are the most favourable for the intensification of barley seed germination. In these modes, plants sprout and develop better. The effect of ultrasound on the dynamics of water absorption by barley seeds in the course of swelling was studied. It was shown that by changing the intensity and duration of ultrasonic treatment, it is possible to control the dynamics of water absorption and to affect the process of barley germination.