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The article is devoted to the search for ways to reduce carbon dioxide emissions in the technological operation of plowing. Ways to reduce CO2 emissions were determined on the basis of computational experiments conducted using a mathematical model of an arable unit compiled according to the efficiency criterion - the minimum integral emission of carbon dioxide. Integral CO2 emission, in addition to direct and indirect CO2 emissions over the life cycle of the arable unit, includes CO2, which could be absorbed from the atmosphere by the crop lost due to the influence of the parameters of the unit. The influence of the parameters of the tractor and the unit on the emission of carbon dioxide during its manufacture, technical and production operation is analyzed. Computational experiments were conducted to identify the influence of some external factors (field area, seasonal load volume, etc.) on the efficiency of the arable unit.

The article discusses the questions of optimization of parameters and operating modes of the tractor as a part of the arable unit by various criteria of optimization. The following parameters have been chosen for consideration. These are minimum total energy costs, taking into account the energy of the lost crop; minimum emission of carbon dioxide into the atmosphere; minimum fuel consumption per 1 ha of crops; maximum performance; maximum traction efficiency of the tractor. The optimal weight of the tractor, the power of its engine, the width of the sowing unit and its working speed were determined by carrying out computational experiments with a change in the resistivity of the sowing complex. It was revealed that the optimal parameters of the tractor and the sowing unit do not coincide according to all optimization criteria with an increase in the specific resistance of the soil to the working bodies of the seeder, the optimal value of the tractor weight and the power of its engine grow. The optimal weight of the tractor should be 120 kN with the possibility of loading up to 150 kN, it is desirable to have a two-level engine of 500 and 600 hp. The working width of the seeder must be able to change from 14 to 18 m.

The article deals with issues related to the reduction of carbon dioxide emissions into the atmosphere during the operation of sowing machine and tractor units. To identify ways to reduce CO2 emissions, computational experiments were conducted using a mathematical model of sowing units compiled according to the efficiency indicator. This is the integral emission of carbon dioxide as the sum of CO2 in the manufacture, maintenance, repair, control of the unit, when burning fuel and the amount of CO2 not absorbed from the atmosphere during the formation of the grain crop due to its losses from improperly selected equipment and its parameters. The influence of a number of factors on the integral emission of CO2 is investigated. These are the area of the treated area or field, the specific resistance of the planter, the volume of seasonal load on the unit, the annual load of the tractor in hours, the physical and mechanical properties of the soil, the pressure in the tires of the wheel propulsion engines, etc. Effective values of factors for reducing the emission of carbon dioxide by the sowing unit are revealed. The use of the totality of all the recommendations received will reduce the emission of carbon dioxide into the atmosphere by the aggregate during the technological operation of direct sowing of grain crops by 600-650 kg/ha.

The relevance of the problem under study is due to the need to substantiate the sufficient number of tractors used for various technological operations, depending on the volume of works performed, and taking into account their influence on the crop yield. The purpose is to develop the mathematical model of machine and tractor units used in technological operations by formalizing the vague concept of optimal agrotechnical timing of technological operations and calculating the optimal number of tractors to perform works by the total energy costs. The main research method is mathematical modeling of operations performed by machine-tractor units based on the system analysis and computational experiments and using the energy mathematical model. The article describes a criterion for optimizing the tractor parameters, dependences of the energy mathematical model of the unit. The results of computational experiments showed that for each operation there is an optimal number of tractors and tractor units minimizing the minimum total energy costs. Calculations were carried out when treating 1000 hectares with various tractors. It was revealed that the total energy consumption differs by 2 or more times. The required number of tractors depends on their main parameters, propeller parameters and other factors. It was revealed that with an increase in the volume of works, the required optimal number of tractors increases. The method for substantiating the required optimal number of tractors in technological operations will improve operations of tractors used by large agricultural producers, reduce the total energy costs for cultivating up to 12–16 thousand MJ/ha.

The topic is relevant due to the need to improve basic measurements of tractors, considering a major contribution they make to crop production, not only during separate technological operations, but also during a whole sequence of technological operations performed. The paper analyzes the limits to which the basic measurements of tractors (weight and engine power), which are used to perform a combination of technological operations requiring different energy consumption, can be altered and to identify practical limits to perform a combination of low and high energy-consuming activities. The key research method used is mathematical modeling based on system analysis and computational experiments that are carried out using models of implements during various technological operations. The results of calculations analyzed for technological operations that differ in the amount of energy consumed suggest that for each of the groups of technological operations that require similar amount of energy (soil resistivity per meter of working width, kN/m), there are fairly stable values of the basic measurements of tractors. A reasonable weight for tractors to perform operations such as harrowing, continuous cultivation of soil with a resistivity of 1 to 4 kN/m is 35-60 kN. For soil preparation with a resistivity of 4 to 8 kN/m it is 100-120 kN, for plowing with a resistivity from 10 to 16.25 kN/m – equal to 160 kN, for tillage with subsoilers with a resistivity from 8 to 16 kN/m – equal to 240 kN. Once put to practice, the findings will lead to a decrease in total energy consumption to 10,000 MJ/ha. The amount of saved energy costs depends on the type of technological operation, the parameters of tractors used, the characteristics of agricultural implements, soil properties, etc.

The article presents the results of a study to identify the optimal value of the annual load on one tractor using direct sowing technology. The optimal annual load on one tractor is directly associated with the power provision to agriculture and, indirectly, with its productivity. The article analyzes the dependence of the annual tractor load in ploughland per ha on various factors of the tractor-operator-instrument-fieldsoil-crop system: on tractor parameters; unit; environment and it is concluded that the optimal annual load on one tractor depends on them. The method of choosing various agricultural enterprises power supply should be connected with the natural and climatic conditions of their production activities, accepted technologies for cultivating crops, soil types, field sizes, etc. It was revealed that in Russia the optimal energy supply of agriculture with the power of tractor engines, using the zero tillage technology, is in the range from 2.4 to 2.8 hp/ha.

When assessing the cause of torsional vibrations on the crankshaft of tractor engines, forced vibrations are taken into account, which are provoked by torques arising from each cylinder and transmitted to the connecting rod necks, taking into account the order of operation of the cylinders. Researchers have only calculated or experimental values of the torque for different angular positions of the crankshaft with a certain sampling step. The algorithm for solving the torsional vibration problem involves the decomposition of discrete values of the torque of one cylinder into a harmonic series in order to determine its amplitudes and phase shifts. The adequacy of the resulting decomposition is determined by the number of harmonics taken into account and, as a rule, includes 10-12 harmonics. At the same time, it is necessary to perform such decompositions for each speed and load mode, which increases the amount of calculations. An algorithm is proposed that considers these modes separately, and depending on the values of the gas and inertial forces, allows using the characteristics of the nominal operating mode and the decomposition with a smaller number of terms. In this case, the results of the expansions have a satisfactory convergence. The proposed method for determining the parameters of motor harmonics of exciting moments under changing speed and load modes of the internal combustion engine, can be useful in the design of new and fine-tuning dampers of torsional vibrations of crankshafts.