The paper considers a method of growing potato and Jerusalem artichoke minitubers in a water-air environment under artificial lighting. When growing minitubers, use was made of aerohydroponics modules, variable mode of power supply and various nutrients depending on the growth and development stage of plants. The studies have revealed the characteristics of growth, plant development and tuber formation, the analysis of the harvest structure of minitubers obtained in the water-air environmentunder artificial lighting. The average number of standard minitubers per one plant was 15.3 pcs. for the early Zhukovsky variety, 17 pcs. for the Red Scarlett variety, 8.7 pcs. for the Innovator variety and 11 pcs. for the Natasha variety. The average number of minitubers for the Skorospelka artichoke variety per one plant amounted to 17.3 pcs. In the result, the authors have founded that the use of aerohydroplane devices with a combined power supply system in the cultivation of original seeds under artificial lighting allows to reach the following goals: to increase quantitative yield of minitubers per a plant; to reduce the cost of a unit of production as compared with traditional methods of the production of minitubers in a pot-plantgreenhouse environment. The production of one mintuber of potato and Jerusalem artichoke has taken 1.35 and 1.38 kW of electricity, respectively. The authors have experimentally confirmed the feasibility of using this method, which allows to regulate the process of tuber formation and make the most favorable conditions for the cultivation of minitubers.

The paper considers the design features of separating elements of units for harvesting root crops and onion. The authors describe a designscheme of a rodconveyor with an asymmetrical passive elliptical shaker and a supporting roller that ensure reduced damage to produced root crops and onion bulbs under a maximum separation mode. The results of theoretical studies of the rod conveyor are based on the determination of design and technological parameters in its interaction with aheap of root crops and onion bulbs. The basic design and technological parameters of the considered rod conveyor have been determined. The authors have derived a formulatofind the inter axial distance between the elliptical shaker and the supporting roller as well as the supporting rollerdiameter. Dependencies have been established to determine the absolute speed of the root crops at the maximum possible raising angle of the rodconveyor belt. The results of experimental studies make it possible to state that the completeness of the seed onion heap separation in optimum modes is 95...97% with a damage of up to 1.3%, which corresponds to the existing recommendations for onion harvesting.

The authors have conducted theoretical study of the movement of material particles in the space between a rotating drum surface and a tangential extraction device deck to determine the velocity of moving particles.The authors claim that to separate clover seeds from shells, it is advantageous to use a device acting under the predominant influence of friction forces. The peculiarity of the considered device for extracting grass seeds is that the movement of material and the destruction of seed shells is caused mainly by friction forces. To obtain an analytical description of the process of moving material particles in the space between the rotating deck and the drum surface and determine the velocities of particles, theoretical studies have been carried out. A hypothesis has been put forward that the necessary condition for the movement of material particles is madein case the frictional force between the drum surface and particles reaches a value sufficient to overcome the frictional forces between the particles and a fixed deck. On the basis of the proposed hypothesis the authors have obtained equations allowing to determine the values of angular and linear velocities of a material particle in the tangential device for extracting grass seeds. It has been established that the angular velocity of a particle increases along with an increase in the friction coefficient of the material relating to the drum and decreases along with an increase of the friction coefficient relating to the device deck. As the drum radius increases, the angular velocity decreases as well. The linear velocity of a particle at the inlet of the extracting device is minimal, and the maximum value is observed at the device outlet. The linear velocity increases as the drum radius increases. The equations obtained as a result of the studyallow to determine the values of angular and linear velocities of material particles enteringthe tangential device for extracting grass seeds.

According to the previously developed mathematical model that determines the accuracy parameters of land works, the authors have made an analysis of the accuracy of performed works taking into account cutting forces. The former mathematical model of the working mechanism of the Chetra EGP-230 power shovel actuatorhas been supplemented by dynamic characteristics. A working processcyclogram has been designed, and basing on it, an influence of each hydraulic cylinder of the working mechanism on the accuracy of a longitudinal profile of the developed trench bottom has beenevaluated. The authors have also estimated the value deviation of the generalized input coordinate from the time determined by the hydraulic cylinder rod displacement under the action of forces as well as from the theoretical value specified by the control action. The found discrepancy of displacements along the generalized coordinate from the hydraulic cylinder rod and the theoretical control action also affects the coordinates of the output impact on the cutting edge of the working mechanism bucket. The coordinatevalues of the input and output effects, taking account of the dynamic characteristics of the working mechanism and a possible delay in the hydraulic drive action, can significantly differ from the theoretical values, which inevitably leads to the inaccuracy of excavation works, thus being an additional source of errors in the shape of a longitudinal profile of the trench bottom. If the dynamic characteristics of the working mechanism are taken into account, the difference between the specified and actual positions is 0.0892 m. In the meanwhile, total dynamic error in the cutting edge position of the working mechanism bucket, taking account of cutting forces and a possible delay of the hydraulic drive action, is 0.1176 m. The value obtained exceeds the required value (0.05 m) in more than 2 times. Basing on the simulation results, it has been found that the compliance of all elements with technical requirements does not guarantee the compliance with the required accuracy of the output element (shovel) movement.It means that an insufficient amount ofearthat the trench bottom may exceed the required value (0.05 m), or increased excavation may be done, so further land reclamation worksmay become impossible.

To assess the impact of a technological level of the machine and tractor fleet on the efficiency of grain production and state the relationships, the authors have determined a complexindicator of technological properties including compositefactors - technological versatility, agrotechnical properties, productive performance capability, the cost of process executionand the level of comfort. The data of enterprises of the Georgievsk district of the Stavropol region have been used in the research. Using the correlation analysis and logarithmic approximation, the authors have stated a close relationship between the technological level of the tractor fleet and the cost of production. The value of the correlation coefficient has amounted to 0.74. The calculatedregression equation allowed determining the estimated losses from the incompliance of the technological level of the fleet with modern requirements. Compact geographic location has allowed considering major and minor expenditure items not related to the machinery fleet as constant values. Taking account of gross harvest of cereal crops in 2017 and the estimated cost of 1 t of grain, the authors have stated a loss of 317.7 million rub. Results characterizing the incompliance of the technological level indicator with the maximum value in the area, stress the necessity to upgrade the existing fleetwith high-tech versatile tractors.

The authors have worked out a methodology for rationalizing the relocation frequency of mobile fleets. The paper presents an economic efficiency evaluation of using a mobile fleet of farm machinery taking into account specific features of agricultural production. It is proposed to combine all machinery employed into two groups, since they require additional expenses for daily moving to work locations and back. An experimental verification of the procedure for substantiating the periodicity and frequency of relocating mobile farm machinery fleet has been carried out and the effectiveness of its use in agricultural production has been confirmed. The authors have introduced a factor of 0.85 to reflect the share of costs in the cost of machine-shifts, accounting for the transportation of machines, obtained the formula and calculated the radius of the optimal range of mobile fleet, which is equal to 173.6 conventional referencehectares. The costs of fleet equipment mounting and dismountinghave been determined, as well as the cost of works for the fleetrelocation, which is equal to 782,960,46 rubles. As a result of the experimental verification of theoretical provisions, the operability and feasibility of determining the periodicity and frequency of farm machinery fleet relocation have been exemplified by the experience gained in the Tambov region. It has been established that a company can get significant financial savings in the amount of 1,012,150.86 rubles (in the basic prices of 2001). In the prices of 2017, the economic effect exceeds 6,072,905.16 rubles.

At present, economic interests of product manufacturers and consumers are the main criteria for choosing measuring instruments. Loss reduction from internal and external faultscan be ensured through the detection of measurement discrepancies, as well as by reducing the defects of the 1st and 2nd kind, which are manifested due to the presence of measurement errors. The authors have worked out a methodology for determining the economic efficiency from the use of a new measuring instrument as compared with the conventional (basic) one, which includes all the parameters characterizing the losses due toinaccurate measurements, monitoring costs and the cost of measuring instruments. Choosing measurement instruments for controlling shaft diameters of a unified reducer produced by Mosselmash has been offered as an example. The ИЧ-10 indicator that used to be employed before in the C-III rack when adjusting by the end gauge rods of Grade 3 (with an error of 8 μm) is proposed to be replaced with the bracket CР-25 in the rack when adjusting by the end measures of Grade 2 (with an error of 3.5 μm). As a result of the economic effictassessment, it has been revealed that the number of incorrectly accepted and rejected parts has been reduced in almost 3 times. The economic effect has amounted to 92,704.89 rubleswith the control program of 3000 pcs. a year. The study has confirmed the expediency of using a more accurate means of measurement, which allows increasing the efficiency and result rating of input and output inspection at a technical service enterprise.

The paper considers conceptual provisions of the scientific support of improving economic partnership relations on the basis of mutual interest; as well asregularities of scientific-and-technical progress causing continuous improvement of equipment, technology and the organization of production. The authors provide grounds for the use ofassessment methods of the changing machinery quality in the course of its service life. The considered costs as a cost model expressing a methodological approach to assessing the machine performance do not reflect any changes in the machine performance quality in the course of its use, a decrease in fuel efficiency and comfort, as well as anincreased complexity of operation due to increasing physical wear and tear. To specify the service life expectancy of a machine, to make economic assessment of its wear and tear and residual value, as well as to evaluate its changing performance quality, there is a need to adjust the calculation procedures. This correction is based on the dynamics of annual "compensating" costs and "leveling" charges per unit of work (services)performed.It has been shown that the refinement of a methodology of economic evaluation of real wear and tear and the machine performancequalityis one of the tools of the regulatingmechanism of market relations.

The paper underlines the urgency of the economic evaluation and pricing for agricultural machinery, as well as its influence on the production and supply of farm enterprises with machinery. The activities of western and eastern firms determine the negative trends in domestic farm machinery market. The authors show some shortcomings of the currently used techniques of the economic evaluation of farm machinery and offer a methodical approach based on taking account of the price level of agricultural outputs produced using the evaluated equipment and the minimum level of profitability that provides conditions for extended reproduction. The paper presents the results of the technique approbation as exemplified by the RSM-161 combine harvester used for harvesting spring wheat and spring barley. It is stated that using a combine for harvesting these crops is impractical, since the actual operating costs exceed the maximum permissible ones and, as a consequence, the consumers’ money spent to purchase the combine do not pay off. Though the economic effect is produced as can be seen from the comparison of the "basic model" with the "new one" for the reduced costs. Introducing the limits of the effective use of technology and improving the economic evaluation of machinery will allow avoiding losses in the production process and ensuring the profitability level sufficient for extended reproduction of farm enterprises. It has been established that the criteria for reduced costs provide only the comparative effectiveness of various machinery options, and the limits of economic efficiency are represented by the effectiveness of machinery use in specific conditions of agricultural production.

The paper deals with the main problems of increasing labor productivity. The author analyzes the influence of material and technical factors associated with the implementation of scientific and technical progress achievements on the increase in labor productivity. The author outlines the study results of the basic indexes of some indicators of agricultural production in Russia that influence labor productivity. The analysis of machinery and equipment renewal in agriculture has been carried out. The author suggests considering a promising direction of improving the efficiency of agricultural production and decreasing the specific composition of resource requirements through the development and adoption of resource-saving technologies and methods of agricultural crop cultivation. To solve this problem, the author has developed and evaluated the ridge-making technology and the performance of a row-crop cultivator for row-crop cultivation. It has been revealed that in terms of economics the most advantageous is the ridging technology of row-crop cultivation. Its use results in an additional net income ofcorn growing of 6195 rubles per 1 hectare of crop area, sunflower growing - 9135 rubles, soybean growing - 4240 rublesas compared with the conventionalcultivation technology. This technology can be considered resource-saving, which is an important factor of increasing production efficiency and labor productivity. The author stresses that the introduction of scientific and technological progress should be accelerated, otherwise poor material and technical facilities of agricultural enterprises in the future will be insufficient to ensure higher rates of productivity growth.

Thуpaper introduces some features of water behavior in the electric field of a small intensity. It has been found that plain water can retain forsome time an electric charge given to it before, i.e. there is an effect of a distinctive electric memory. This effect has never been described before. To make an experiment, use has been made of a water element consisting of an AA battery,a multimer, carbon electrodes, a stopwatch, a water bath, two switches and copper wires. When current flows,there is a voltage on the water element electrodes equal to that of the battery. If the electrodes are disconnected from the battery and connected to the voltmeter, the voltmeter pointer first sharply falls below a certain value, then slowly moves to the zero point. Readings of a galvanometer connected as a second switch to the electrodes instead of the voltmeter testify that the voltage value still remains greater than zerofor some time. Low voltages remained on the electrodes in the experiments for up to a few minutes that can be considered an evidence of electric water memory. The described phenomena can serve as a verification of a dipole model of water molecules and a manifestation of electrolytic dissociation. The author stresses the influence of the distance between electrodes on the residual voltage value of the switch. The shorter the distanceis, the higher voltage is observed. It has been also noticed that water quality has an influence on the voltageamount: distilled water used to fill the batteries gives lower values of switching voltage as compared to tap water.

The paper considers a possibility of partial utilization of excessive kinetic energy of a liquid coolant in solar systems. The kinetic energy of a moving fluid is transformed into rotational energy of the impeller and can then be used in a mechanical or electrical form. Basing on the dependence analysis of water density on temperature, the set values of the coolant temperature at the collector inlet and outlet, and the geometric parameters of the solar system, the authors have determined the power developed by the impeller installed in the closed pipeline. Factors influencing the amount of this power have been revealed, and a conclusion has been made about the role of the right coolant use. The authors consider a number of common liquids that can be used asa coolant in solar systems. The authors state the main requirements made for the coolant: a maximum density difference at the boundaries of the operating temperature range, low viscosity, constancy of the phase state, sufficient heat capacity, no aggressive properties with respect to the material of the impeller and pipes, environmental friendliness, harmless use by the personnel, explosion and fire-proof features, cheapness and ability to preserve the listed properties for a long time. As a result of the analysis includingone and a half dozen liquids, conclusionshave been made about 1) the most effective use of propylene glycol, and 2) the influence of the operating features of solar systems on the choice of coolant.