It was noted that when forming the configurations of an unmanned aerial system for pesticide and fertilizer application, it is necessary to take into account the interdependence of unmanned and ground-based aerial systems. (Research purpose) To develop the configurations of an unmanned aerial system for pesticide and fertilizer application. (Materials and methods) The authors used Methodological recommendations on the use of chemicals in the precision farming system (VIM), regulatory and technical documentation for unmanned aerial systems. (Results and discussion) The authors developed a flowchart of the algorithm for forming the configurations of a helicopter type unmanned aerial system for fertilizer and pesticide application, including the formation of both unmanned and ground-based aerial systems. The authors calculated the aerodynamic characteristics of an unmanned coaxial rotor aircraft with a take-off weight of 280 kilograms and a payload of 100 kilograms. A modular-designed sprayer was offered. The authors substantiated the structure of the ground-based aerial complex in the form of a mobile transporter-tanker with a basic transport platform, lifting and transporting and refueling modules, and a universal ground control panel for the pilot-operator. (Conclusions) The authors formed reasonable configurations of a helicopter type unmanned aerial system for pesticide and fertilizer differentiated application in the precision farming system. Aircraft performance limitations were identified for the application of fertilizers and pesticides by a helicopter type unmanned aerial vehicle: the payload of at least 100 kilograms, the operating altitude of 1.0-1.5 meters when bypassing the agricultural field topography and avoiding possible obstacles, the operating airspeed kept below 60 kilometers per hour, automatic take-off and landing on a limited area, autoflight at the speed of 60 kilometers per hour at a one meter altitude in a tacking mode. It was showed that the static ceiling margin, without taking the earth influence into account, with a 280-kilogram flight mass, is 1300 meters, which allows flying in mountainous areas, for example, for the treatment of vineyards with pesticides.

Digital agricultural production is based on robotic agricultural technologies for the use of pesticides and fertilizers using unmanned aerial systems, which are based on unmanned aerial vehicles for monitoring agricultural land, the pesticides application, fertilizers and other agrochemicals. (Research purpose) To develop an unmanned helicopter based aircraft for applying pesticides and fertilizers, and to substantiate its technological parameters. (Materials and methods) The authors used methodological recommendations on the use of chemicals in the precision farming system, regulatory and technical documentation for unmanned aircraft systems. (Results and discussion) The authors determined the unmanned aerial vehicle main flight technical and technological parameters for the implementation of the applying pesticides and fertilizers process. They established the dependences of its productivity on the norms of introducing working fluids of pesticides and fertilizers, the agricultural field length, and the approach distance to the field. (Conclusions) The authors developed a helicopter-type unmanned aerial vehicle of a coaxial design with a take-off mass of 280 kilograms and a payload of 50-80 kilograms, a rotor diameter of 5.3 meters, a constructive boom width with sprayers of 5 meters, a working flight height of 1-5 meters, a working speed of 40-60 kilometers per hour, the rate of working fluid of pesticides application 10-20 liters per hectare and nitrogen fertilizers 30-120 liters per hectare. They established rational values for the application rates of pesticides – 10-20 liters per hectare, the agricultural field length – at least 0.8 kilometers, ensuring maximum productivity in flight hour when processing the agricultural field. They showed that the flight distance minimizing from the runway to the field significantly increased the productivity of applying pesticides and fertilizers.