China's agricultural machinery development has gone through fi ve stages in its 100-year history: Germination stage of agricultural machinery development (1917-1949), Construction Stage of Modern Agricultural Machinery Industry System in China (1949-1979), System transformation Stage (1980-1995), Market-oriented stage (1996-2003), Rapid development stage (2004-2014). After the 12th Five-Year Plan, China's 13th Five-Year Plan has been going on for three years. Signifi cant Achievements in Agricultural Mechanization has also made in recent 10 years. Although Agricultural Mechanization in China has made considerable progress, there are still great gaps in agricultural mechanization level compared with developed countries. In order to further narrow the gap between China's agricultural mechanization and developed countries, enhance the scientifi c and technological innovation ability of agricultural machinery, strategic focus of agricultural mechanization have been presented in China. The development strategy of "three steps" is defi ned, that is, the strategic objectives of China's agricultural machinery science and technology innovation and agricultural mechanization development to 2025, 2035 and 2050. Two Development Principles which are full process mechanization and Comprehensive mechanization, and from 1.0 to 4.0 of China Agricultural machinery are emphasized in China.

Excessive and unbalanced use of the pesticides that is necessary to protect agrophytocenoses against pests leads to environmental pollution. Harmful pesticides tend to enter the natural cycles of substances. Therefore, they are quick to disappear or be destructed by biological agents. There are also “nondestructive” pesticides, which do not enter the natural cycles; neither they are accumulated in food chains and in biotopes. These substances have become an object of research in the fi eld of environmental safety.

To develop the theory and practice of operation procedures in a greenhouse, a mathematical model of indoor plant lighting is required. (Research purpose) Development of a simulation and analysis technique of energy-and-ecological compatibility of indoor plant lighting. (Materials and methods) The authors experimentally verifi ed the proposed technique for the indoor plant lighting of tomato seedlings grown under laboratory conditions with controlled environmental parameters. An irradiator consisting of a LED matrix with secondary optics and a driver was used. The photoperiod amounted to 16 hours. The experiment was completed for 46 days. The technique includes an analysis of the energy conversion effi ciency at various stages in the blocks of the artifi cial bioenergy system of indoor plant lighting (ABES): a source of electrical power; a radiation source; an optical part; spatial fl ow distribution; surface fl ow distribution; and a plant. The authors proposed formulas for calculating the energy consumption of each ABES unit. It was revealed that for the estimated values of the energy consumption of ABES blocks taken according to expert estimates, the total energy consumption accounts for 0.32-2.27 megajoule per one gramme of wet weight of a plant, i.e. diff ers by almost an order of magnitude, depending on the specifi c implementation of the lighting technology. It is shown that optimization cannot be limited by consistent selection of an option with the lowest value of energy consumption at each stage, but requires fi nding the optimal route on the graph of options. (Results and discussion) For the experimental conditions, the total energy consumption of ABES was 3.77 megajoule per one gramme of the wet weight of a plant. The low effi ciency was caused by the unsatisfactory effi ciency of the LED matrix and the low productivity of the plant photosynthesis. (Conclusions) The developed technique for modeling and analyzing the energy-and-ecological compatibility of indoor plant lighting allowed assessing possible energy saving at each stage of energy and substance conversion in indoor plant lighting. Theoretically, possible reduction of losses in the source of electrical power is 22 percent, in the optical part – 14 percent; in spatial fl ow distribution – 16 percent; in surface fl ow distribution – 10 percent. Possible increasing of the lighting source effi ciency depends on the achieved level of technology, which currently provides an output of 2.5 micromole per joule and more. To increase the productivity of indoor plant lighting, it is necessary to precisely match the parameters of the lighting mode and the requirements of plants.

Better fi eld operations are performed result in lower weed contamination of crops, which means less chemical protection is required. This makes a positive eff ect on soil fertility, crop quality and the ecological situation in general. (Research purpose) To study weed circulation in mechanized farm technologies for cereal production and propose ways of reducing the weed content at all stages of cultivation, taking into account the favorable environmental response of the agricultural background. (Materials and methods) The authors have revealed the fundamental criteria for the implementation of fi eld operations based on a multifactorial model of crop cultivation: reduction of the weed content, reduction of soil compaction sites and re-processing, and environmenta response. They have demonstrated weed circulation in traditional cereal production technologies, identifi ed the development dynamics of weeds and their distribution in the agricultural background. (Results and discussion) The authors controlled weed seeds on spring wheat fi elds under production conditions during the harvest seasons of 2016 and 2017. They experimentally found an increased content of miliary weed seeds in the selected threshing products, the mass of which ranged from 5 to 16 grams per m2. The share of weed seeds in grain hopper amounted to 2.9 percent. It was revealed that weed seeds isolated by a combine remain viable after autumn tillage. Transverse tillage increases the area of contamination in 2 times or more. The authors propose a comprehensive system of weed control at all stages of fi eld operations, taking into account the environmental response of the agricultural background. It is shown that the separation and destruction of weed seeds at the harvest stage is of particular importance. The authors present technical and technological solutions to reduce weeds and ensure a favorable ecological situation. (Conclusions) The authors have designed a comprehensive system to reduce weed contamination, thus reducing the overall impact of plant protection remedies by 30 percent.

Development and testing of new more effi cient and environmentally friendly waste management technologies is one of the priorities of agroecology aimed at introducing the basic principles of the sustainable use of natural resources. An example of such a technology may be the recycling of cattle manure into the bedding for farm animals. (Research purpose) Feasibility study of diff erent technological options for the production of bedding from manure under conditions of an operating livestock enterprise. (Materials and methods) In the study, three options of this technology were considered as exemplifi ed by a dairy farm for 100 milking cows: Option 1 – separation of manure into fractions followed by aerobic fermentation of the solid manure fraction in a drum-type fermentor; Option 2 – mixing the unprocessed manure with peat and its subsequent aerobic fermentation in a drumtype fermentor; Option 3 – mixing the unprocessed manure with peat and its subsequent aerobic fermentation in a chambertype fermentor. The author has estimated capital and operation costs as well as labour inputs and payback period. (Results and discussion) The number of facilities and equipment required for manure recycling and the resulting product storage has been calculated for each option. The author has made an economic assessment of the three options. For Option 1, the capital costs of implementation amount to 18.2 million roubles, operating costs – 8.9 million roubles, labour inputs – 5.1 man-hour per tonne, and the payback period – 2.1 years. It has been revealed that options 2 and 3 feature high capital costs, therefore, bedding production with the use of peat proved to be ineffi cient. (Conclusions) The study has allowed to determine the most effi cient and economically feasible technological method of manure recycling: manure separation into fractions with subsequent aerobic fermentation of the solid fraction in a drum-type fermentor. Options 2 and 3 have been found economically unfeasible.

In the world practice of introducing solid mineral fertilizers, almost 90 percents of the machines used are equipped fertilizer application is about 10 percents. It has been still confi rmed that their small width of application results in insuffi cient productivity, and in practice they are not used for introducing the main amount of fertilizers in pre-sowing soil preparation. (Research purpose) Designing a pneumatic sucker-rod machine providing for increased uniformity of fertilizer dispersing when introducing the main amount of fertilizers and further dressing vegetative plants. (Materials and methods) The authors obtained relationships allowing to determine rational constructive-and-kinematic parameters of a device for fertilizer metering and distributing through ejectors and dispersing surfaces using the laws and methods of classical mechanics and mathematics. Experimental studies were carried out using a developed and manufactured sample, and testing its operability in fi eld conditions using standard and specifi c techniques. It was determined that the quality of fertilizer dispersing with a pneumatic sucker-rod machine is mainly aff ected by the uniformity of their supply by reel-type units to the air stream and rods with holes, and the pattern of fertilizer distribution to ejectors depending on the distance between them. (Results and discussion) The authors have made patterns of fertilizer transportation and metering with reel-type sowing units and determined the method and pattern of distributing an air-mineral mixture through the rod channels. The authors obtained a mathematical description of the processes of mineral fertilizer application, taking into account the qualitative indicators of their uniform dispersion over the fi eld surface. It was noted that the uneven distribution of fertilizers when the rod length is appropriate corresponds to the design standards. (Conclusions) The authors have revealed that the rate of distribution unevenness of ammonium nitrate amounted to 8 percents. It has been found that even at the machinery designing stage it is possible to evaluate performance indicators in terms of unevenness depending on the metering quality and the distance between sowing ejectors.

The authors have described the required conditions for uniform soil tillage at a given depth. It has been shown that depth wheels of tillage machines should be constantly pressed to the soil surface. The study has confi rmed the need to determine the optimal value of the vertical pressure force exerted by the depth wheels on the soil. (Research purpose) To determine ways to ensure the given depth of tillage and the required uniformity using a mounted plow with a depth wheel. (Materials and methods) The authors conducted theoretical studies using methods of theoretical and agricultural mechanics, as well as analytical geometry. They made a diagram of forces acting on the plow in the process of plowing. (Results and discussion) The authors obtained an analytical relationship to determine the vertical pressure force exerted on the soil by a depth wheel of a mounted plow taking into account dimensions and parameters of a tractor mounting system as well as a plow mounting linkage. The optimal values of vertical distance from the plow supporting plane to its lower connecting points were graphically determined. The authors calculated the optimal numerical values of the parameters taken into account: the vertical distance from the tractor's supporting plane to the attachment point of the lower links of its attachment mechanism is 0.6 meters; the number of bodies installed on a plow – 4; the weight of one plow body is 250 kilograms; the plow effi ciency – 0.7; plowing (tillage) depth – 0.3 meters; horizontal distance from the lower connecting points of the plow to the share point of the fi rst body – 0.45 meter; longitudinal distance between the plow bodies – 1.0 meter; plow landside width – 0.2 meters; coeffi cient of rolling resistance to the depth wheel of the plow – 0.2; the diameter of the depth wheel – 0.5 meters etc. (Conclusions) It has been established that in order to ensure a required plowing depth and uniformity, vertical distance from the supporting plane of four-body plows coupled with 3-4 class wheeled tractors to the lower connecting points should be within 0.703-0.771 meters.

The most important task in designing competitive agricultural machinery is the production of parts with long service life. The development of new technologies and materials determines the technical level of agricultural engineering. The plowshare blade is the most loaded and important part, as its parameters determine the quality, energy and economic indicators of the technological operation of plowing. (Research purpose) To determine and confi rm theoretically material and technological parameters of low quality level of domestic plowshares manufactured without the use of modern technologies. Then they analyze construction materials of plowshares and other parts of tillage implements produced by leading foreign companies, and come to a conclusion that lowand medium-carbon boron-containing alloyed and high-alloyed steels are used in their production. Leading global manufacturers of machine parts also often apply surface hardfacing with carbide coatings. (Results and discussion) The authors have theoretically and experimentally determined the directions of increasing the strength and durability of plowshare working tools. They have chosen basic materials for plowshares basing mainly on the strength parameters. They have conducted comparative laboratory tests of various materials and witness samples (including double-layer ones) for abrasive wear resistance on two bench installations; identifi ed materials for carbide coatings, clarifi ed the relative wear resistance coeffi cients of steel carbide layers recommended for use in the design of plowshares; and considered a technological method of hardening machine working tools. (Conclusions) The authors propose a simplifi ed computational procedure for selecting design and material parameters (thickness and width of hardening coatings) of plowshare blades and over-chisels, depending on the wear characteristics of the materials used and the plowshare thickness. They have stated mathematical relationships that determine the linear wear of plowshare blades and chisels depending on the characteristics of the materials used, design parameters, soil conditions and total operation time and carried out comparative operational and duration testing of newly developed plowshares. It has been shown that the marginal operating time of new products exceeds the duration indicators of serial counterparts in diff erent soil and climatic conditions in 3.5-5.5 times.

In order to ensure high-quality sowing and smooth seed germination, the main task in pre-sowing soil preparation is fi eld surface leveling, soil compaction to the required degree and the formation of a mildly mulching layer on the soil surface. For combined implementation of these operations, a leveler-ripper has been designed. (Research Purpose) Determination of cuttingedge angles, the inter-leg length and width of the shanks of a leveler-ripper (Materials and Methods) Theoretical studies were carried out using the methods of higher mathematics and theoretical mechanics. The authors obtained analytical dependences that help determine the rational values of the cutting-edge angle of the shanks and their inter-leg width. (Results and Discussion) It has been shown that the front part of a leveler aligns the unevenness of fi eld surface, and the rear part compacts the soil. At the same time, the lumps located on the soil surface are partially crushed with the shanks and partially pressed into the soil. As a result, a mulching layer about 4-6 centimeters thick is formed. The shank length was taken equal to the sowing depth of cotton seeds. The authors determined the cutting-edge angle of the shanks proceeding from the condition of no soil build-up in front of them and no soil sticking to their working surface. (Conclusions) It has been revealed that to ensure quality soil preparation for sowing with minimal energy consumption, the cutting-edge angle of the shanks of a leveler-ripper should be in the range of 54-66 degrees. Taking into account that a leveler-ripper is used mainly for soil preparation for cotton sowing, and cotton seeds are sealed at a depth of 4-6 centimeters, the shank length can take an average of 5 centimeters. It has been calculated that the inter-leg width should not exceed 10 centimeters.

Palm oil is comparable to traditional diesel fuel in terms of calorifi c value, stoichiometric ratio, and cetane number. However, its increased kinematic viscosity and pour point make it diffi cult to use in pure form in diesel engines. (Research purpose) To study specifi c features of burning: diesel fuel with various additives of palm oil (biodiesel fuel); pure 100-percent palm oil; biodiesel fuel with various additives of palm oil and hydrogen peroxide, as well as to develop a method to control its combustion process. (Materials and methods) To determine the ignition time lag, the authors chose a method of kinetic modeling of self-ignition of biodiesel fuel in the air. The self-ignition process was simulated using the Chemical Workbench software package. An adiabatic calorimetric bomb model was used to perform calculations. To describe the process of self-ignition, a universal kinetic mechanism was used, which was verifi ed to calculate self-ignition of diesel and biodiesel fuel surrogates, as well as the formation of toxic substances and soot in the combustion processes. (Results and discussion) It is shown that adding palm oil to diesel fuel increases its ignition time lag, especially at low and medium temperatures of 750-950 kelvin. It was determined that with addition of 10 percent palm oil, the ignition time lag of biodiesel fuel is almost the same as that of diesel fuel no more than 5 percent. Increasing the amount of palm oil additive up to 30 percent and more signifi cantly increases the ignition time lag of the fuel. When using only palm oil as a fuel, the ignition time lag in the temperature range of 800-950 kelvin increases in two times. The study determined the optimal amount of hydrogen peroxide to be used for each composition of biodiesel fuel with various additives of palm oil. (Conclusions) It is shown that additives of hydrogen peroxide can infl uence the reactivity of biodiesel fuel and thereby regulate its ignition time lag.