• 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.

  • 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.

  • 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

  • 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%.

  • 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.

  • Factors determining the quality of main and pre-sowing treatment of tomato growing soil

    pg(s) 83-85

    This is a review of the groups of factors influencing the quality of the main and pre-sowing tillage of the soil for growing tomatoes – soil-climatic, technological.
    The paper performs an analysis of the a priori information and from the conducted experimental researches the connection between the separate factors and the quality for performing the basic and pre-sowing treatment of the soil for growing tomatoes was established.

  • Hydrometric monitoring of rivers and canals-technological innovations

    pg(s) 81-82

    The protection of soils and waters is an extremely important issue for humanity. The main task to be done by the scientific staff is to monitor and control the water quantities leaving the water management facilities. Measurements of kinematic quantities can be used not only for quantitative assessment of runoff, but also for verification of theoretically derived hydraulic dependency in different forms of water movement. They are the basis for experimental determination of a number of theoretically introduced coefficients measurement of the hydraulic quantities determining them. Hydro metric measurement of non-pressure currents is a specific activity that has gained wide application around the world. When determining the water quantities, observations of the river outflow are made, also the measured parameters can be used for other engineering tasks in the construction of hydro technical facilities.[1]

  • Efficiency of irrigation in growing tomatoes in greenhouse conditions

    pg(s) 78-80

    Irrigation plays a key role in growing vegetable crops. The efficiency of irrigation is expressed in obtaining optimal yields in terms of quantity and quality. The use of water resources should be water and energy saving in order to reduce the costs of vegetable production and to be environmentally friendly. The main criteria for assessing the effectiveness of irrigation are the total and additional net incomes. In order to meet the set requirements for irrigation, the best effect is obtained by applying drip irrigation. When growing tomatoes, the value of the irrigation system is redeemed in the first year for areas over 5 dka, for areas below 5 dka it takes 2 years. Drip irrigation of tomatoes has shown that the frequency and size of irrigation rates affect the weight, diameter and length of the fruit, their number and hardness.


    pg(s) 238-241

    Granular materials are a collection of distinct macroscopic particles. Consequently soils, which are used for agricultural purposes are a part of them. In comparison with other simulation models, creating a numerical simulation with the discrete element method (DEM) for different soils prove to be difficult. The reason for this is that there are an enormous number of particles. Therefore it is not possible to reproduce every one of them. On this account, parcels are used in the numerical simulation. These are larger and also have different physical properties. However, also for the modelling of parcels characteristic variables are necessary. This variable should be determined by using the capillary effect.


    pg(s) 235-237

    The paper analyzes the results of research in the sector of mechanization for the evaluation of efficiency of deposition of dispersed drops of fluid on the treated surface when using conventional hydraulic nozzles and rotating disk atomizers, mesh or perforated drums with the forced deposition of small drops. The necessity of using forced deposition of small droplets when creating new working bodies to the spraying technique on the basis of the rotating disc atomizers, mesh, or perforated.


    pg(s) 232-234

    Promising energy technology means for controlled traffic farming are wide span tractor (vehicles). The effectiveness of the practical use of wide span tractor (vehicles) depends on a sound scientific base or theoretical frameworks, concerning the study of their technological properties. The article presents the theoretical basis of the dynamics of plane-parallel movement wide span tractor (vehicles) in the horizontal and vertical plane as well as its cornering. Developed the theory of plane-parallel movement wide span tractor (vehicle) allows for the justification of new schemes, design parameters and operating modes with acceptable controllability and stability of motion in the horizontal plane. Ride wide span tractor (vehicles), as a dynamical system, moving through the traces of permanent tramlines significantly depends on the characteristics of the irregularities of the longitudinal profile. The desired character of the internal structure of the longitudinal profile laid tramlines is almost possible to obtain the appropriate technology for its formation. Quality testing of dynamic system input perturbations, which are irregularities of the longitudinal profile permanent tramlines and the unevenness of the traction resistance of the soil, depends on the scheme and the constructive and other settings wide span tractor (vehicles). A significant impact on thesmoothness of the latter renders the rigidity of the tire support wheels, the magnitude of which can be influenced, within certain limits, by changing the air pressure in them. Improve driving dynamics the technological part of the wide span tractor (vehicles) is observed by increasing the rigidity of the tire its supporting wheels and operating mass. The offered new scheme of the turn of a wide span tractor (vehicle) for controlled traffic farming on the turning strip by turning the undercarriage, using the steerable wheels from its one board around the turning centre arranged in the centre of the space between the wheels from the other board, allows shifting of the tractor, simultaneously with the turn, to the next operating position with better kinematic parameters. In addition to it, the improvement of the turnability characteristics is achieved at such a design embodiment of the wide span tractor (vehicle) when the relation of its wheelbase to the width of the wheeltrack is as small as possible.


    pg(s) 223-231

    The contribution was to develop methods for irrigation management using knowledge in the field of precision agriculture. In the monitoring points were established basic hydrolimits: Field capacity (FC) and wilting point (WP). Irrigation rate ranged from 0 to 40 mm for a specific term assessment of soil moisture. Throughout the growing season used to be applied precisely five irrigation benefits. A high savings were observed between conventional and precise irrigation (water, energy and economic savings). The results show that it is a fully effective system of precision agriculture, although the procurement and introduction of new technology and the software requires first expending a considerable financial cost. Higher demands are placed on the skill and education services.