Table of Contents


    • Study of the oscillation processes of a front-mounted haulm harvester when it moves on the inequalities of the ground surface

      pg(s) 86-90

      In the article the calculated mathematical model of oscillations of the haulm-harvesting machine frontally attached to a wheeled tractor is constructed. A nonlinear differential equation is obtained, which describes the oscillations of a haulm-harvesting machine in the longitudinal-vertical plane during the movement of its pneumatic copying wheels along the unevenness of the soil surface. On the basis of the received theoretical results rational constructive and kinematic parameters of the front-mounted hoisting machine which provide decrease in amplitude of the specified fluctuations are defined. So, at translational speed of movement of the haulm-harvesting unit V = 3.0 m∙s–1, the amplitude of oscillations of the rotor of the haulm harvester decreases in 1.2…1.5 times in comparison with height of roughnesses of a surface of the field o h = ± 0.04 m. At the amplitude of oscillations of the lower ends of the knives of the rotary cutting device up to 4 cm, the loss of the tip does not increase significantly. However, when increasing the values of the amplitude of these oscillations to 7 cm or more, the loss of the branch increases significantly and the maximum values of which exceed 12%.

    • Justification of the improved technological process and development of the construction of the cleaner of root tubers from impurities

      pg(s) 91-93

      The paper presents a new construction of a root ball cleaner from impurities, consisting of five wave-shaped working spirals, which are given oscillatory movements with appropriate amplitudes and frequencies in the longitudinal-vertical plane. It allows to considerably expand a working zone of separation of the potato heap arriving on clearing, and it will promote its better dispersion on a working surface of the cleaner, more intensive destruction of ground clods, and consequently, improvement of sifting of ground and vegetative admixtures and decrease of blocking of working spirals. All this ultimately increases the productivity and quality of the new root crop cleaner from impurities. To carry out experimental studies of the new construction of the cleaner of potato roots from impurities, we have developed a laboratory setup, which allows you to test and justify the basic constructional and kinematic parameters of this cleaner. The process of cleaning of root crops from soil impurities and plant residues indicated cleaner is due to the movement of the heap coils cantilevered spiral springs, which rotate at a certain angular velocity, and the oscillatory motion of the springs themselves, arising from the deflection of their longitudinal axes. In this case, soil and plant impurities are sifted through the separating gaps and coils of spirals, and the bodies of potatoes are transported by coils of spirals in the direction of the unloading conveyor. Calculations of the required power for the drive of the laboratory unit showed that it does not exceed 1.3 kW.

    • Application of polymer composites in moving joints machines of the fat and oil industry

      pg(s) 94-96

      The expediency of using parts made of polymer composites in moving joints of machines in the oil and fat industry is shown. The use of experimental moving joints provided an increase in the resource from 500 hours to 1080 hours minimum. Diagnostics of experimental moving joints revealed that some of them have signs of transfer of the composite material to the steel shaft. This is explained by the following factors: the presence of the transfer effect and operation at high temperatures of 140 °C. The operating modes of the equipment are maintained. Most of the experimental parts made of polymer-composite material are in a running-in state, as wear has not been recorded in them.


    • Influence of different forms of sulphur fertilizers on the content of mineral nitrogen in the soil and productivity of winter wheat

      pg(s) 97-99

      The research was performed in 2019-2020 LAMMC at Rumokai Experimental Station of the Lithuanian Research Centre for Agriculture and Forestry. The soil was calcaric luvisol, the granulometric composition was a silt loam on clay Winter wheat, after resumption of vegetation fertilized UAN-32 (control), Leader 24-6 and KAS-32 + Thio-Sul (N12S26). Nitrogen active substance: 60 + 60 + 30. Mineral nitrogen in the soil was investigated twice: during the grain milk stage of wheat and after harvest. In the grain milk stage in 2019 Leader 24-6 reduced mineral nitrogen by 6.7-47.6 %, UAN-32 + Thio-Sul – 21.6-28.7 %. 2020 – 58.0-42.3 % and 26.3-19.8 % (depending on the number of uses). After harvesting, mineral nitrogen was found in the fields where sulfur fertilizers were used 5.13-49.2 % less than in the control fields. The use of Thio-Sul had a positive effect on protein content.

    • Influence of grandma’s teeth compost (tribulus spp.) on the distribution of soil microorganisms

      pg(s) 100-102

      The influence of compost from grandma’s teeth (Tribulus spp.) оn the distribution of main groups of microorganisms in two soil types – Alluvial – meadow and Cinnamon forest soils was tested. Three levels of fertilization were applied, and soil microorganisms were reported on days 15, 30 and 45 after compost application. It was found that the most suitable for expression of soil biological activity is the introduction of compost in the content of 5% -10%.

    • Use of modern innovative technology for monitoring rivers and springs to determine water quantity

      pg(s) 103-104

      Researchers monitor rivers and springs to predict what part of the water resources to use for irrigation for industry, drinking needs to maintain ecosystems. The main task of the scientific staff is to monitor and control the water quantities coming out freely from natural caverns, rock crevices, free-flowing rivers and springs. The measurements of kinematic quantities, can serve not only for the quantitative evaluation of the runoff, but also for the verification of the theoretically derived hydraulic dependencies in the different forms of water movement. When determining the water quantities, observations of the runoff are carried out, as well as the measured parameters can serve to play an important role in the construction of water management facilities

    • Evapotranspiration of pepper grown in unheated greenhouses under drip irrigation

      pg(s) 105-107

      To determine the evapotranspiration of the pepper, variety “Golden Medal” grown in plastic unheated greenhouses in an experimental test field in Chelopechene, Sofia region, irrigation options were tested from fully satisfying the crop’s water needs to 20% and 30% increased irrigation of irrigation rates and a variant irrigated with 100% irrigation rate. An environmentally friendly and watersaving irrigation technique was used. The evapotranspiration of the culture and the evaporation from a free water surface were experimentally determined. Based on the calculated values of evapotranspiration and evaporation from a free water surface (evaporation) determined by a class “A” evaporation pan, the values of the biological coefficient of the culture in unheated plastic greenhouses were calculated, and the average for the vegetation period of pepper is 1.35.

    • Irrigation regime of pepper grown in unheated greenhouses with drip irrigation

      pg(s) 108-109

      In order to establish the irrigation regime of pepper variety “Gold Medal”, grown in plastic unheated greenhouses in the Chelopechene experimental field, Sofia district, irrigation options were tested from fully satisfying the water needs of the crop /100% irrigation rate/ to irrigation with 20% and with a 30% increase in irrigation rates. A water-saving irrigation technology is used. The highest yield of 4879 kg/dka was obtained when using 130% irrigation rate, followed by the variant with 120% irrigation rate – 4460 kg/dka on average for the research period. The yield in the variant irrigated by class “A” evaporation pan, approaches the yield obtained in the variant with 100% implementation of the irrigation rate.