Sirvi Autor "Ivanovs, S." järgi

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Assessment of the greenhouse gas emissions and energy inputs applying different weed control methods for wheat growing
(Estonian University of Life Sciences, 2023) Zagorska, V.; Ruciņš, A.; Viesturs, D.; Ivanovs, S.
Economic indicators are often used to evaluate and select technologies, determining the production costs of the product. However, according to the EU's green course, the ecological assessment of technologies is increasingly important. The purpose of the article is to comparatively evaluate two winter wheat weed control methods, which are widely used in Latvia, according to two ecological indicators - the amount of the GHG emissions and the energy consumption, to find out whether these indicators can serve as a criterion for the selection of technologies. These two methods are HA (harrowing), in which weeds are controlled by harrowing and herbicides, HE (herbicides), in which weeds are controlled only by herbicides. The methodology for calculating the mentioned indicators was developed by analyzing several studies by other authors. The total GHG emissions generated are calculated as the sum of five components: emissions, generated for the manufacture and delivery of the machinery used; emissions, generated by the fuel, consumed for implementation of the technology; emissions, generated for the production, delivery and installation of fertilizers; emissions, generated for the production, delivery and installation of pesticides, seed production, delivery and installation emissions. Analogously, the total energy consumption is calculated by summing the components The technologies were implemented on a specific farm, with the machinery of this farm, labor, fertilizers and the plant protection products. It has been established that the technologies differ by the calculated ecological indicators within the range of 1.2–2.6%; moreover, these indicators are lower for the technology with the herbicide spraying, and the technology is simpler to implement. Therefore, it is also more widely used. Since the coefficients for the calculation of the ecological indicators can be applied by the methodology of this article, the characteristics of the technique and the doses of fertilizers and the plant protection agents, used on the farms, are known, the ecological indicators can be used as an additional criterion for the selection of technologies on the farms. The ratio of the energy value and energy consumption of the produced product (the output and the input ratio) was also determined, this indicator for technologies HA and HE being, respectively, 8.30 and 8.41. In comparison with the research by the authors in other countries, from the point of view of the amount of the generated CO2-eq emissions and rational consumption of energy, the analysed winter wheat production technologies are evaluated as moderately efficient, but from the point of view of the energy value of the product produced and the ratio of the energy consumption (the output and the input ratio) - as efficient.
The efficiency of nitrogen fertilizer on the dry matter yield of tall fescue and festulolium grown as feedstock for combustion
(2019) Adamovics, A.; Platace, R.; Ivanovs, S.; Gulbe, I.
Grass biomass grows during one vegetation season and can be cultivated and consumed at the place of breeding. Grass biomass can be used not only in traditional feed, but, recently, also for energy production (biogas, solid fuels). The most important economic indicator for any crop is its productivity. The study found that it is important to use nitrogen fertilizer to increase the productivity of tall fescue and festulolium. A significant increase (p < 0.05) in the yield of tall fescue was observed starting from the nitrogen norm of 60 kg ha-1 N. Further increase in nitrogen fertilizer norm provides a significant increase in dry mater yield of tall fescue (reaching 8.64 t ha-1 ) and festulolium (reaching 8.11 t ha-1 ) at 180 kg ha-1 N. The analysis of linear regression coefficients of polynomials showed that the highest nitrogen efficiency in the first year of the use of tall fescue was achieved at the norm of 180 kg ha-1 N, but for festulolium – at the norm of 120 kg ha-1 N. In the following years of tall fescue use, the highest efficiency of nitrogen norms differed: in the 2nd and 4th year of use – at 60 kg ha-1 N, in the 3rd year of use – at 30 kg ha-1 N, and in the 5th year of use – at 120 kg ha-1 N. In contrast, for festulolium, in the 2nd year of use, the highest nitrogen efficiency was reached at the norm of 30 kg ha-1 N, and in the 3rd–5th year of use – at the norm of 60 kg ha-1 N.
Experimental investigation of the work of a ploughing aggregate, operating according to the system ‘push- pull’
(2018) Bulgakov, V.; Ivanovs, S.; Arak, Margus; Kuvachоv, V.; Shymko, L.; Bandura, V.; Estonian University of Life Sciences. Institute of Technology
The use of ploughing machine - and - tractor aggregates, operating according to the principle of ‘push - pull’ , finds increasing application in the world since it allows ensuring the stability of the movement and the depth of ploughing, reduction of the energy indicators. The aim of this experimental study is to determine under field conditions the dynamic and ope rational technological parameters of the ploughing machine - and - tractor aggregate, operating according to the ‘push - pull’ system. This aggregate was an integral ploughing - tillage wheeled HTZ 16131 tractor, in front of which there was mounted a two - bottom pl ough, and at the rear – four - bottom ploughs. This aggregate has satisfactory path parameters of the movement during the execution of the technological process of ploughing. The oscillations of the furrow path for this aggregate are of a low - frequency natur e and are concentrated in a rather narrow frequency range (0...50 m - 1 ). At the operating speed of 2.0 m ∙ s - 1 it is 0...0.16 Hz. The maximum value of the mutual correlation function between the input impact (the turning angle of the driven wheels of the aggr egating tractor) and the output value – its relative bearing is positive and reaches a value of 0.88. Stability of the ploughing depth for the aggregate according to the ‘2 + 4’ scheme is ± 1.65 cm 2 , which is normally the smaller value of the same indicato r for a serial ploughing aggregate (± 1.98 cm 2 ).
Experimental study of an improved root crop cleaner from admixtures
(2018) Bulgakov, V.; Ivanovs, S.; Nowak, J.; Bandura, V.; Nesvidomin, A.; Ihnatiev, Ye.
One of the ways to raise the quality of sugar beet harvesting is the use of improved digging tools that are able to dig out root crops from the soil without any loss and considerable damage, as well as cleaners of the heap from admixtures. Perspective are the root crop harvesting machines, built according to the modular principle, where, depending on the state of the beet plantation, the composition of the cleaning tools, and the kinematic and technological modes of their operat ion are determined. To carry out experimental studies, experimental equipment was made which, under laboratory and field conditions, made it possible to obtain qualitative separation indicators of the heaps of sugar beet roots with wide variation in the ra nge of kinematic and design parameters of the improved cleaner. As the results of the laboratory and field experimental studies showed, in each of the two stages of cleaning the beet heap, a sufficiently high degree of removal of the soil admixtures and pl ant residues is ensured. Thus, at the first, preliminary stage of cleaning, the removal of admixtures amounted to 65.5 – 75.8%. After the second, basic stage of cleaning, the transported heap contained no more than 1.9% of admixtures. The results of the laboratory and field tests indicate that the proposed design of an improved sugar beet root cleaner from admixtures is prospective.
Investigations about the impact of the sowing time and rate of the biomass yield and quality of industrial hemp
(2017) Adamovics, A.; Ivanovs, S.; Bulgakov, V.
The aim of this study was to find the optimum sowing rate of industrial hemp (Cannabis sativa L.) and to clarify the impact of the sowing rate on the production of biofuel from hemp biomass in Latvia. Field trials were carried out at the Research and Study Farm ‘Pēterlauki’ of the Latvia University of Agriculture in 2012–2014. The industrial hemp (Cannabis sativa L.) ‘Futura 75’ was sown in a Luvic Endogleyic Stagnosol soil: pHKCl 6.7; P – 52 mg kg-1 ; K – 128 mg kg-1 ; the organic matter content – 21–25 g kg-1 . Hemp was sown in 10-m2 plots, triplicate, on May 8 and 17. The total sowing rate was 20 (100), 30 (150), 40 (200), 50 (250), 60 (300), 70 (350), 80 (400), 90 (450), and 100 (500) kg ha-1 (germinating seeds per 1 m2 ). The plots were fertilised as follows: N – 120 kg ha-1 ; P2O5 – 80 kg ha-1 ; and K2O – 112 kg ha-1 . Hemp was harvested when the first matured seeds appeared. The biometrical indices (height and stem diameter), harvesting time, the amount of fresh and dry biomass, and the fibre content were evaluated. Depending on the sowing rate, the yield of dry matter was on average 9.2–12.1 t ha-1 when hemp was sown at the beginning of May, and 7.9–10.0 t ha-1 when hemp was sown in the middle of May.
Research into geometric parameters of digging shares used for lifting sugar beet roots from soil with assistance of vibration
(2021) Bulgakov, V.; Holovach, I.; Adamchuk, V.; Ivanovs, S.; Melnik, V.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
One of the important conditions in securing the high quality, when performing the work process of vibrational root lifting, is to avoid damaging the roots. It is obvious that the greatest probability of damaging and even breaking the lifted root arises, when the tool interacts with the root body during their first contact and in the time of the root passing in the throat between the operating shares. The aim of the study is to substantiate the rational design length for the working throat of the vibrational root lifter in its interaction with the sugar beet root while lifting the latter from the soil. As a result of the completed research, the minimum permissible tool oscillation frequencies have been determined for the specific values of the lifter’s translational velocity and the working throat rear part length, at which the event of the vibrational lifting tool gripping the root will occur at least one time. For example, when the length of the lifter’s working throat rear part is equal to 0.1 m and the oscillation frequency is equal to ν = 20.3 Hz, the satisfactory quality of the vibrational root lifting process is ensured, when the velocity of the translational motion performed by the vibrational lifter stays within the range of 1.3–2.55 m s –1 . In order to ensure the good quality of the vibrational root lifting process at the lifter’s translational velocity equal to V = 2.0 m s –1 and the frequency of its tool’s oscillations equal to ν = 10 Hz, it is necessary that the length of the lifter’s working throat rear part is equal to 0.2 m, at a tool oscillation frequency of 6.7 Hz - 0.3 m. As a result of the completed numerical calculations, the permissible values have been determined for the tool oscillation frequency, which can be recommended for the translational velocities within the range of 1.3–2.2 m s –1 , taking into account the limitation set for the tool oscillation frequency by the pre-condition of the guaranteed gripping of each root by the digging shares.
Resistance of the soft winter wheat varieties to pests and their productivity in the northern forest-steppe zone
(Estonian University of Life Sciences, 2024) Polishchuk, S.; Holyk, L.; Havryliuk, N.; Kuzmenko, L.; Shtakal, M.; Tkachenko, N.; Bulgakov, V.; Ivanovs, S.; Rucins, A.
There are highlighted the results of research in order to determine the field and laboratory resistance of the winter wheat varieties in a competitive variety testing at the National Scientific Centre Institute of Agriculture of NAAS (2016–2020) against pests, and the level of their productivity is assessed. Among the studied varieties of winter wheat, varieties with complex resistance were found: to cereal aphids, wheat thrips powdery mildew and brown leaf rust - variety Efektna; to cereal aphids, wheat thrips and leaf rust - varieties Polisianka, Pyriatynka, Krasunia Poliska, Vodohrai, Kesariia Poliska, Myroliubna, Romanivna, Pamiati Hirka, and standard Lisova Pisnia St. When varieties were grown without the use of fungicides, insecticides and growth regulators, their yield varied over the years from 2.99 t ha–1 to 10.71 t ha–1. The best varieties of soft winter wheat in terms of their productivity were identified in the northern Forest - Steppe zone, which are included in the State Register of the plant varieties, suitable for distribution in Ukraine - Kesariia Poliska (7.67 t ha–1), Pyriatynka (7.10 t ha–1), Myroliubna (7.08 t ha–1), Merezhka (6.77 t ha–1), Kraeivyd (6.71 t ha–1), Pamiati Hirka (6.61 t ha–1), Polisianka (6.51 t ha–1) and Efektna (6.36 t ha–1). Consequently, with proper selection of the winter wheat varieties, it is possible to significantly limit the harmfulness of pests and diseases, to reduce the amount of the used pesticides, to increase the grain productivity, and to improve its commercial and seed quality.
Results of experimental investigations of a flexible active harrow with loosening teeth
(2019) Bulgakov, V.; Kaletnik, H.; Goncharuk, I.; Ivanovs, S.; Usenko, M.
Soil tillage processes significantly affect the growth of cultivated plants; therefore, improvement of various designs and combinations of ploughs is still an actual practical and scientific task. This paper presents investigations of the design of a soil tillage machine consisting of three plough bodies equipped from the lateral side with a module with a flexible active harrow driven by a support wheel. The technological process of tillage by this machine is carried out in such a way that the module of the flexible active harrow is installed at a certain depth of soil tillage. The purpose of this work is an experimental comparative investigation of the quality indicators of the work of a design of the soil tillage working body with a flexible active harrow having loosening teeth. In the process of comparative experimental investigations of the operation of ploughs with a standard flexible harrow and an experimental active harrow having loosening teeth, the soil lumpiness (characterising the quality of crumbling) and water permeability of the obtained soil structure were estimated. An experimental model of this working tool was tested under the production conditions, and it showed advantages of loosening and crumpling the soil compared to the conventional harrows. This can be explained by the fact that the harrow tines, freely mounted on the axes of its links, ensure their oscillatory movements when moving in two different planes, thereby creating conditions for more intense soil disintegration.
Some morphological and chemical characteristics of oregano (Origanum vulgare L.) in Latvia
(2019) Sivicka, I.; Adamovics, A.; Ivanovs, S.; Osinska, E.
By European Cooperative Programme for Plant Genetic Resources (ECPGR), oregano (Origanum vulgare L.) is included on the list of priority species of medicinal and aromatic plants. In Latvia, it is important to cultivate oregano for keeping biodiversity and for meeting the needs of medicinal plant`s production. 44 accessions of oregano from the ex situ collection of genetic resources of medicinal and aromatic plants, attached to the Latvia University of Life Sciences and Technologies, were analysed during 2012–2014. Plants` morphological characteristics were described by the Draft Descriptor List of oregano, using the methodology of ECPGR. The essential oil was isolated using solvent-free microwave extraction method and analysed by gas chromatograph Hewlett Packard 6890 equipped with flame ionization detector FID and polar capillary column HP 20M. The results showed, that oregano accessions differ morphologically. Accessions are characterized with dense branching and the possibility to create big biomass. Local oregano is poor in content of essential oil, but 17 compounds were identified as the principal. As well as the correlation between the content of essential oil and colour of flowers in full flowering stage was observed – it is higher for accessions with dark flowers. Also, the influence of meteorological conditions per vegetation period (year) on chemical characteristics was significant (p < 0.05).
Study of the controlled motion process of an agricultural wide span vehicle fitted with an automatic driving device
(Estonian University of Life Sciences, 2022) Bulgakov, V.; Olt, Jüri; Pascuzzi, S.; Ivanovs, S.; Kuvachоv, V.; Santoro, F.; Gadzalo, Ia.; Adamchuk, V.; Arak, Margus; Estonian University of Life Sciences. Institute of Forestry and Engineering
The aim of research is to analyse the process of the wide span vehicle motion on the treads of the permanent process track with the use of the traction method of turn. The completed studies have proved that the plane-parallel motion of a wide span vehicle solely with the use of the traction method of turn on the treads of the permanent process track requires a significantly smaller difference between the moments applied to the wheels on the right side and on the left side of the vehicle, as compared to that of a crawler tractor. This difference is in proportion to the width of its wheel base that has a relatively smaller length. It has been established that the use of solely tractionbased turn does not provide for the adjustment of the motion trajectory through the lateral (planeparallel) displacement of the fore-and-aft axis of the agricultural wide span vehicle. The oscillations in the lateral displacement of the agricultural wide span vehicle in the process of its motion are lowfrequency ones. The main variance spectrum of these oscillations is concentrated within the range of frequencies of 0–2 s −1. At the same time, the maximum transverse displacement of the agricultural wide span vehicle equal to 1.3 10−5 m N−1, occurs also at low frequencies. In view of the fact that the main variance spectrum of the oscillations of the tangential forces applied to the wheels on the left and right sides of the agricultural wide span vehicle is concentrated exactly within a low frequency range, only the high accuracy of the system using a laser beam can ensure its satisfactory steerability.
Theoretical research of force interaction of a flexible cleaning blade with a beet root head
(2019) Bulgakov, V.; Ivanovs, S.; Arak, Margus; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The most common technology of removing the sugar beet haulm in the world is a continuous cut of the entire mass of the green haulm with further additional removal of the upper parts of the sugar beet heads, which is carried out without extracting the roots from the ground. This is the scheme according to which most top harvesting machines, manufactured in the world, now operate. However, we have found in our studies that, due to additional cutting off the upper parts of the root crop heads, up to 10% of the sugar-bearing mass is lost. Besides, there is an urgent need for immediate processing of the sugar beet root crops, as losses of the sugar juice occur, and bacteria enter inside of the root crop through the cut-off part, causing rotting. Therefore, a more favourable operation for harvesting root crop tops is not cutting off their heads but cleaning them from the residues of the foliage. In addition, the operation of cleaning the sugar beet roots from the residues of the foliage is subject to rather high requirements due to the absence of the green and dry residues on the heads of the roots, as well as the losses and damage of the root crops themselves. The purpose of this investigation is to develop a theory of the force interaction of the flexible cleaning blade with the sugar beet head in the process of its cleaning when the blade is mounted on the vertical driving shaft. The methods used of the investigation are those of modelling, higher mathematics and theoretical mechanics, as well as programming and numerical calculations on the computer. As a result of the research, an equivalent scheme was developed and a mathematical model was constructed describing the force interaction of the flexible cleaning blade with the surface of the sugar beet root.
Theory of grain mixture particle motion during aspiration separation
(2020) Bulgakov, V.; Nikolaenko, S.; Holovach, I.; Adamchuk, V.; Kiurchev, S.; Ivanovs, S.; Olt, Jüri; Estonian University of Life Sciences
The practice of separating grain mixtures with the use of the difference in the aerodynamic properties of their components has proved that the process of separating mixtures in the aspiration separator is the most promising one with regard to the improvement of quality and intensification of production. The authors have developed a new improved design of aspiration seed separators, in which the work process of separating seed material is performed with the use of vibration processes. In this seed material separator, the constant force air flow that acts on the sail members on the central pipe of the separator, when seeds are fed for processing, generates self-excited oscillations in the pipe, which produces centrifugal forces of inertia in the seed feeding system. As a result of the mentioned effect, the propelling force in the process under study substantially increases, accelerating the seeds of different fractions, which differ in their masses, to different velocities. The motion paths of the seed particles change accordingly, heavier particles moving closer to the vertical axis of the aspiration channel, which provides for increasing the efficiency of separation of the seeds of different fractions from each other. In this paper, a new mathematical model is developed for the motion of a seed mixture material particle in the operating space of the separator’s aspiration channel. The mathematical modelling of the process of vibration and aspiration separation has indicated that the separation of the motion paths of the medium and heavy fractions takes place within the range of 20–40 mm; the flying speed of the particles is equal to 3.2–8.0 m s–1, respectively; and their acceleration is equal to 1.8– 3.3 m s–2, which provides the necessary conditions for the accurate and high quality separation into the required fractions. In view of the found differences between the kinematic characteristics of the separated fractions of the grain mixture, the diameter of the pipeline for the medium fraction is to be within the range of 90–100 mm, for the heavy fraction – 50–70 mm.

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