FORMATION OF COMBINE HARVESTERS FLEET WITH ACCOUNT OF HARVESTING CONDITIONS
Grain harvesting conditions in the Russian Federation have a significant impact on the actual combine performance. The paper contains the analysis results of the impact of harvesting conditions on the technological work and performance indicators of combine harvesters, as well as on changes in the actual productivity rates in comparison with the rated values provided by manufacturers. It has been found that rated grain mass flowing into combine harvesters is in fact significantly lower than the throughput capacity specified in the manufacturer's data sheet. The value of the reduced grain mass supply, as well as the performance of the combine harvester depend on the yield, straw content, the harvester or swather header pickup width, the field configuration, and other harvesting conditions. The existing system of supplying farm enterprises with combine harvesters is not efficient enough in terms of the formation of their optimal fleet in separate regions and the country as a whole, which hampers grain harvesting in the optimal operation periods. It is necessary for individual enterprises and on the whole country level to form a harvesting equipment fleet depending on the harvesting conditions. The paper presents a rational classification of combine harvesters and windrowers, which is recommended to take into account when choosing the required machinery. The paper also presents the calculated values of reduced supply and combine performance in harvesting wheat, corn, and sunflower, depending on the yield and the header types applied