The article considers the issues of developing electronic models of complex techological machines for soil preparation and direct sowing of grain crops, which reduce metal consumption and increase the manufacturability of the product, both in production and in operation, ensure the best conditions for the growth of crops and a significant increase in yield with maximum simplification of structures compared with analogues. On the basis of electronic models, their physical prototypes were made. Field tests of the machines showed their high efficiency. The combined units developed with the participation of the authors make it possible to implement all operations related to tillage and sowing of grain crops. In one pass, the seeder sows the main crop, small-seeded crop (binary component) and introduces mineral fertilizers, and can also be used when putting abandoned and fallow lands into circulation. Testing of a physical prototype of a combined unit for soil preparation and direct sowing of grain crops with a horizontal arrangement of disks showed that the average yield of winter wheat when using it was more than 68 quintals per hectare, which is 28.5% more than using traditional technology of soil preparation and sowing. Methods of system analysis, mathematical modeling, and experiment planning were used in machine design of the unit. Experimental studies were conducted in the field and laboratory conditions in accordance with existing methods, using modern electronic and mechanical devices. The experimental data were processed in the MathCAD.