The limits of reducing the numerical values of the coefficients of the influence of straw content, moisture, grain contamination, on the change in the throughput of the threshing-separating device and the productivity of the combine are calculated. The boundaries of the probable numerical values of the coefficients of straw content, moisture content and dockage of grain stand have been calculated. The probable boundaries of the numerical values of productivity after an hour of network (ha/h) were calculated, depending on the influence of single and general coefficients. The method for calculating the productivity of combines, depending on the weight of the influence of individual coefficients or their overall effect, is proposed, which will make it possible to predict the likely change in productivity in a particular field and during the harvest period with minimization of biological crop losses. To obtain the resulting coefficient of influence of the state of grain, it should be taken into account that the direction of change in the value of the coefficient of influence must coincide with the direction of its influence on the throughput. That is, the minimum value of moisture, straw content and debris corresponds to the maximum value of the throughput of the threshing-separating device.

The solution of universal, global problems of energy and resource conservation in both mechanical engineering and agro-industrial complex are inextricably linked with the solution of issues of protection of machinery from corrosion. Modern agricultural machinery, and self-propelled combine harvesters in particular, are operated periodically for one or two seasons a year. Most combine harvesters are stored in the open areas of agro-industrial enterprises, and it is exposed to aggressive environmental influences (fluctuations in temperature, humidity, wind, solar radiation, dust and others). The main type of environmental impact on the equipment is atmospheric corrosion and the corrosion wear caused by materials, parts and components, which leads to its premature failure. Thus, the fatigue strength of steel products when stored for 12 months in the open reduces by 28–58%. To ensure temporary corrosion protection of combine harvesters, a large number of conservation and working-conservation oils are used. However, the unresolved number of issues of theoretical and practical nature leads to the unjustified use of protective equipment, which either does not provide the required duration of storage of equipment, or increase the cost of its preservation. Standardized methods of testing anti-corrosion lubricants in the vast majority have a number of disadvantages, the most important of which is that the evaluation of protective properties is carried out in units that do not allow to estimate their service life, but only show the corrosion of the metal.

The solution to the universal, global problems of energy and resource conservation in both the machine building and agricultural sectors is inextricably linked to the solution of the issues of protecting machinery from corrosion. Modern agricultural machinery, and self-propelled combine harvesters in particular, are operated periodically during one or two seasons a year. Most combine harvesters are stored in open areas of agricultural enterprises, and they are exposed to aggressive environmental influences (fluctuations in temperature, humidity, wind, solar radiation, dust, etc.). The main type of environmental impact on machinery is atmospheric corrosion and the corrosion wear of materials, parts and assemblies caused by it, which leads to premature failures. For example, the fatigue strength of steel products decreases by 28-58% when stored for 12 months in an open area. To provide temporary corrosion protection for combine harvesters, a large number of preservation and working-preservation lubricants are used. However, unresolved theoretical and practical issues lead to unreasonable use of protective agents that either do not provide the required storage time for the equipment or increase the cost of its preservation. Standardized test methods for anti-corrosion lubricants have a large number of drawbacks, the most important of which is that the evaluation of protective properties is carried out in units that do not allow to assess their validity period, but only show the amount of metal corrosion.

The article conducts research and generalization of storage efficiency of combine harvesters. The most efficient storage of machines is provided indoors by agro-industrial enterprises. However, about 60% of the combine harvester fleet is stored in open areas. Due to limited economic opportunities in many organizations there are cases of non-compliance with the rules of storage of machines and low quality of work on corrosion protection. Due to corrosion during storage of machines and equipment, their durability is reduced, the complexity of maintenance and repair operations is increased. The most susceptible to corrosion are gear teeth and bush-roller chains, threaded connections, working parts of tillage machines: plowshares, cultivator legs and others. Due to corrosion, the cost of maintaining the fleet increases. Costs for maintenance and repair of working tools of tillage implements in organizations range from 32 to 78% of the cost of machines. In recent years, there has been a tendency to reduce the cost of corrosion protection in the use of waste preservatives. However, there are no specific recommendations in the literature for the preparation of such preservatives and the results of their tests for combine harvesters.