The integration of anaerobic digestion technology into the production chains of livestock enterprises is associated with the challenge of managing organic wastewater (effluent). Existing disposal methods can generate by-product emissions and require substantial material and equipment costs. Plasma treatment of effluent represents a promising alternative technology for reducing such emissions, although several issues remain unresolved. (Research purpose) The study aimed to investigate the effect of discharge plasma on effluent. (Materials and methods) A laboratory setup generating hybrid plasma produced by above-water corona discharges and underwater spark discharges was used. Mesophilic effluent obtained from a pig-breeding enterprise was used as the substrate. (Results and discussion) The use of hybrid plasma resulted in a decrease in the potential of hydrogen from 9 to 6 and an increase in electrical conductivity from 1 to 2 millisiemens per centimeter, while the oxidation–reduction potential rose from 300 to 600 millivolts. These changes correlated with a reduction in gas emissions. A direct correlation was observed between the decrease in the potential of hydrogen and the increase in nitrate concentration from 0 to 600 milligrams per liter, which is associated with nitrate stability and low reactivity. The inverse relationship between acidity changes and nitrogen dioxide content is explained by its participation in reactions with oxygen to produce peroxynitrite. The increase in oxidation-reduction potential shifts the ammonia-ammonium chemical equilibrium toward a non-volatile form, thereby reducing ammonia emissions into the ambient air. When used separately, spark discharges had only a limited effect on the effluent; however, as part of the hybrid plasma system, their contribution was more pronounced, both in changing the electrochemical properties by 3–20 percent, and in increasing the concentration of reactive oxygen and nitrogen species by 7–9 percent compared with corona discharges. (Conclusions) Improved environmental safety, the absence of harmful chemical by-products, reduced gas emissions, foam prevention, and scalability are the main advantages of treatment with hybrid discharge plasma compared with existing wastewater disposal methods.

Modern combing must meet agrotechnical requirements by ensuring complete separation of flax capsules, preventing stem entanglement, and minimizing damage to flax stems. However, existing designs do not fully satisfy these requirements, as the penetration of comb teeth into the flax ribbon causes excessive entanglement and stem damage. (Research purpose) The purpose of the research was to develop a stem-combing device for flax-processing enterprises and to substantiate the rational design parameters and operating modes of the machine. (Materials and methods) A stationary experimental setup equipped with a conveyor for feeding flax ribbons into the combing zone was designed and manufactured. The setup made it possible to simulate the separation of seed capsules from fiber flax stems during the combing process. Fiber flax of the Visit variety was used as the initial plant material in the experiments. Combs with different tooth profiles were tested. (Results and discussion) The experiments were conducted using the methodology of mathematical design of multifactor experiments based on a second-order Box–Behnken design. Among the tested variants, the comb with a circular profile proved to be the most effective. (Conclusions) A combing purity of at least 98.5% for fiber flax ribbons was achieved when using a comb with a circular tooth cross-section, a flax ribbon conveyor speed of 1.25 meters per second, and a comb rotational frequency of 2.8 meter per second. The obtained results can be used in the manufacture of serial combing units for flax processing lines. The proposed unit is suitable for integration into domestic production lines for both long and short flax fiber.

The development of electrified transport is constrained by the lack of unified methods and test stands for evaluating the characteristics of motor-wheel assemblies under conditions close to real operation. A significant limitation of existing analogues is their inability to synchronously record electrical and mechanical parameters under the combined effect of vertical load and horizontal tractive resistance. (Research purpose) The study aimed to develop a dynamometric test stand with a combined loading system and a methodology for comprehensive testing. (Materials and methods) The test stand consists of a frame designed as a movable platform equipped with a motor-wheel assembly and weight platforms used to apply a vertical load, as well as a load simulation platform that generates adjustable tractive resistance. The rear section of the movable platform is flexibly connected to the load simulation platform through a force-measuring unit. A microcontroller unit synchronously records current, voltage, rotational speed, temperature, and time. (Results and discussion) Tests were carried out on asphalt concrete at a wheel load of 300 newtons, a module base length of 0.6 meters, a wheel radius of 0.125 meters, an initial vertical dynamometer reading of 50 newtons, a rolling resistance coefficient of 0.02, and an adhesion coefficient of 0.7. The platform load was varied from 50 to 400 newtons, and the power input from 50 to 600 watts. Kinematic relationships were derived. At a platform load of 100 newtons and a power range of 50–350 watts, the tangential force was 58.7 newtons, the tractive force was 52.7 newtons, the vertical sensor reading was 37.8 newtons, the rolling resistance was 6.0 newtons, and the torque was 7.3 newton-meters. At a platform load of 350 newtons, the tangential force increased to 192 newtons, the tractive force to 186 newtons, while the vertical force decreased to 10 newtons, the rolling resistance remained 6.0 newtons, and the torque reached 24 newton-meters. The torque varied with the platform load and was almost independent of the power input. Slippage was recorded at loads above 384 newtons. (Conclusions) The test stand enables synchronous acquisition of time-dependent electrical and mechanical parameters for evaluating the efficiency of a motorwheel assembly, determining rolling resistance, validating mathematical models, and substantiating control algorithms for traction electric drives over the operating load range.

Keeping calves in individual plastic hutches on outdoor sites offers a number of advantages, but it also involves certain risks. During frosts, cases of frostbite, disease, and animal mortality have been reported. Therefore, for regions with a long cold period of 4–6 months, ensuring heating in individual calf hutches is an important task. (Research purpose) The study aimed to develop a rational design and substantiate the parameters of an electric infrared heater. (Materials and methods) From a thermalenergy perspective, “dark” infrared emitters with a wavelength of 2-5 μm are preferable for heating calves, as they allow the heat flux to be regulated depending on the animal’s position inside the hutch. A calculated relationship was established between the heat flux transferred from the heater to the calf, the temperature of the hutch enclosing structures, and the standard ambient air temperature. (Results and discussion) A functional and technological diagram of a calf-heating system for individual hutches was proposed. The thermal-energy and design parameters of a linear electric infrared heater were substantiated based on a calculated heat-exchange model describing a calf within a system of isothermal, diffusely absorbing and emitting surfaces. The results of physical modelling of the calf heating process under different operating modes are presented, and an operating prototype of the heater was developed. (Conclusions) Physical modelling was used to substantiate the parameters and operating modes of an electric infrared heater for calves housed in individual outdoor hutches during the cold season. A functional diagram was proposed, and an experimental prototype of the heater was manufactured.

The transition of microplants from sterile in vitro conditions to a non-sterile ex vitro environment is accompanied by abrupt changes in microclimatic parameters, particularly humidity and gas exchange. This study presents the development of a climate chamber designed to support the adaptation of micropropagated plants to ex vitro conditions. (Research purpose) The study aimed to experimentally verify the performance of a chamber equipped with programmable LED phytolamps and a precision microclimate control system. (Materials and methods) The adaptation experiments were conducted on regenerated redcurrant plants (Ribes rubrum L.) grown in substrate-filled trays. Microclimatic parameters and the spectral composition of radiation were measured using standardized methods. (Results and discussion) The chamber maintains a temperature range of 10 to 35 degrees Celsius and a relative humidity range of 40 to 95 percent. The temperature change rate is 0.9 degrees Celsius per minute during heating and 0.4 degrees Celsius per minute during cooling, while temperature and relative humidity fluctuations do not exceed ±0.6 degrees Celsius and ±3 percent, respectively. Lighting is provided by LED phytolamps with independent control of four spectral channels: blue, 460 nanometers; red, 660 nanometers; far-red, 720 nanometers; and broad-spectrum white, 400– 700 nanometers, with optional ultraviolet radiation in the 380–400 nanometers range. Photosynthetic photon flux density can be adjusted from 34 to 805.7 micromoles per square meter per second. The chamber is operated through a touch-screen interface that enables manual and automatic control, setpoint programming, smooth light-intensity adjustment, and storage of preset templates. Integration with Internet of Things systems is also supported. (Conclusions) The verified characteristics correspond to the declared parameters, confirming the chamber’s suitability for the effective adaptation of micropropagated plants to ex vitro conditions.

The paper demonstrates that interaction between the threshed material and working elements of a threshing unit leads to changes in its physical and mechanical properties. However, the influence of these changes on the conditions of material capture and retention has not yet been sufficiently investigated. Effective threshing requires reliable capture and stable retention of the material. In maize ear threshing, the efficiency of this process is largely determined by the relationship between the main parameters of combine harvester, its productivity, and power demand, taking into account the physical and mechanical properties of the material. (Research purpose) To establish the relationship between the movement speed of threshing products and the power characteristics of combine harvester during maize grain harvesting. (Materials and methods) In practice, the optimal range of the maximum maize capture angle is established experimentally and depends on ear moisture content and the rotational speed of the working elements. The study examines factors influencing the efficiency of maize grain threshing in the threshing-and-separating unit of a grain combine harvester. Statistical meta-analysis methods were applied to quantitatively integrate the results of scientific studies employing similar methodologies, with the aim of establishing the dependence of threshing quality on crop condition and threshing drum settings. (Results and discussion) The gripping ability of the threshing drum increases with a higher coefficient of friction between the ear and the rasp bar surface and with a lower coefficient of friction between the ear and the concave. It is also established that the moisture content of the material influences the threshing drum speed during operation. The study establishes the dependence of threshing quality on the parameters of the threshing clearances at the inlet and outlet of the concave. It also determines the required power by taking into account the performance of all processes and operations involved in maize grain threshing. (Conclusions) The analysis revealed a dependence between the movement speed of threshing products along the raspbar drum of a maize combine harvester and its power characteristics.

The digitalization of the agro-industrial sector and the growing volume of data generated by agricultural machinery and technological equipment create a demand for intelligent analytical methods capable of capturing nonlinear dynamics and adapting to changing operating modes. Time-series forecasting methods for technological parameters are of particular interest, as they can improve monitoring accuracy and enable the transition to predictive control and maintenance strategies. (Research purpose) The study aims to assess the potential of Long Short-Term Memory (LSTM) recurrent neural networks for short-term forecasting time series of technological parameters in agricultural machinery and equipment, taking into account long-term temporal dependencies and the non-stationary nature of the data. (Materials and methods) The study used telemetric time series obtained during the operation of industrial equipment as the initial data. Training sequences were developed to preserve the temporal context of the observations. Modelling was performed using a recurrent neural network based on the LSTM architecture, which allows long-term dependencies in the data to be captured. Forecasting performance was evaluated using the MAE, MSE, and RMSE metrics. ARIMA models and a fully connected neural network were employed as baseline methods for comparison. (Results and discussion) The developed LSTM model demonstrated high forecasting accuracy, effectively reproducing both stationary segments and transition periods of the time series. The experimental results yielded MAE = 0.0094, MSE = 0.00014, and RMSE = 0.0119, indicating that the proposed LSTM model outperformed the benchmark models. (Conclusions) The results confirm the effectiveness of LSTM-based models for the analysis and forecasting of technological processes and indicate their strong potential for application in industrial monitoring and predictive control systems.

Weed control should be regarded as one of the key technological operations in organic crop production, along with the application of biological plant protection agents and the localized placement of organic fertilizers. Mechanized equipment currently available for row-crop cultivation is primarily designed to remove weeds from the inter-row space. However, 15–20 percent of weeds may remain within the crop rows, in the spaces between cultivated plants. (Research purpose) The study aimed to develop a structural and technological diagram and an operating algorithm for an automated sectional working unit for in-row weed removal in potato crops, using digital solutions based on machine learning and computer vision. (Materials and methods) A distinctive feature of in-row weed control in potato crops is that the weeding blade must periodically move into and out of the ridge during operation. This imposes specific requirements on the blade design, its geometric parameters, and the drive system. A system for controlling the blade working depth is also required to maintain stable operation under variable soil-contact conditions. (Results and discussion) An information model of the weed removal process was proposed. The model describes how design, technological, technical, and environmental parameters affect weed removal efficiency, crop damage, and energy consumption during the operation. A structural and technological diagram was developed, and an operating algorithm for the automated sectional working unit was compiled. (Conclusions) The study determined how the force acting on the side cutting edges of the weeding blade depends on the inclination angle of these edges and the working depth during blade entry into and exit from the ridge. Under the optimal blade parameters, this force should not exceed 38.2 newtons. The proposed process model enables accurate estimation of the loads acting on the weeding blade drive and supports the rational selection of its operating parameters.

Unmanned aircraft systems are becoming one of the key technologies in the digital transformation of the agro-industrial sector, enabling timely monitoring of agricultural land and the acquisition of up-to-date information on its condition. (Research purpose) The study aimed to conduct a retrospective analysis to identify the main trends in the development of UAV flight control systems and aerial imaging equipment for agricultural land monitoring. (Materials and methods) A retrospective analysis was carried out based on a systematic literature review. Original works by Russian and foreign authors were examined, along with monographs, conference proceedings, museum exhibits, photographic documents, and open-source software code. (Results and discussion) Six stages were identified in the development of UAV flight control systems and aerial imaging equipment used for agricultural land monitoring. The proposed periodization is based on changes in the types of image data collected, the cameras employed, and the aircraft on which they were installed. For each stage, the main trends in the development of UAV flight control systems and aerial imaging equipment were determined, including UAV type, flight range and endurance, flight control system, imaging equipment, type and number of images obtained, and the aircraft used for data collection. Based on the analysis, further directions for the development of unmanned aircraft systems were identified. (Conclusions) The development of UAV flight control systems and aerial imaging equipment proceeded in parallel until cameras were integrated directly on board aircraft. The study showed that camera miniaturization and the improvement of flight controllers have played a key role in this development, ensuring high-accuracy aerial imaging data and enabling timely monitoring of agricultural land. Further development of onboard intelligent systems and aerial imaging equipment is expected to lead to the full automation of data collection and processing, thereby enabling high-precision real-time monitoring.

The expansion of blackcurrant production was limited by the lack of machinery for cultivating and harvesting this crop. The paper presents information on the development of mechanized blackcurrant harvesting in Russia since the 1960s. (Research purpose) The study aimed to analyze the main historical stages in the development of domestic berry harvesters designed for intermittent and continuous operation and to summarize the results of their trials in order to determine the parameters of the MPYa-1 harvester. (Materials and methods) The study was based on an analysis of scientific and technical literature and reports on the mechanization of berry harvesting in the USSR in the second half of the 20th century, using historical-analytical and comparative methods. (Results and discussion) The study describes the technical features of the working components of laboratory units used to identify optimal operating modes for detaching blackcurrant berries. This made it possible to scientifically substantiate the parameters of future machines. The designs of the experimental models MYaG-000, PYaM-000, PYaM-71–73, and the first production combine harvester, MPYa-1, are analysed. The paper presents the results of state and comparative trials. It compares the performance indicators of the MPYa-1 harvester and its counterparts: the KK-1 (Bulgaria) and the Pattenden (United Kingdom), tested on the blackcurrant varieties Golubka, Bogatyr, and Pobeda. It was found that the MPYa-1 berry harvester ensured berry detachment completeness of 95.8-97.9 percent and a berry collection rate of up to 88.4 percent. The impurity content, 0.68-2.1 percent, was significantly lower than that of the British counterpart, 9.2 percent, indicating a more advanced separation system. Labour productivity increased 73-fold compared with manual harvesting. The optimal vibration parameters were determined as a frequency of 15-17 hertz and an amplitude of 20-25 millimeters, at which a gentle fruit-detachment mode was achieved. (Conclusions) The trial results confirm the high efficiency of the MPYa-1 berry harvester and the feasibility of its serial production for plantations with row spacings of 2.5-3 meters, the findings also demonstrate the effectiveness of a systematic approach to solving the problem of mechanization in horticulture.

The article examines the activities of the Agrophysical Research Institute during the first decade following its establishment. (Research purpose) The study aims to examine and summarize, for the first time, archival materials on the activities of the Agrophysical Institute during the Siege of Leningrad, from autumn 1941 to 1944. (Materials and methods) The historical and scientific study is based on reports documenting the activities of the Agrophysical Institute stored in the Central State Archive of Scientific and Technical Documentation of St. Petersburg, as well as on published monographs and articles concerning the work of Russian scientists during the Siege of Leningrad. (Results and discussion) The study systematizes information on the institute’s key scientists and their contributions to the development of agrophysical science. It identifies research groups according to their subject areas and leading researchers. The institute’s staff carried out dedicated work aimed at solving practical problems in agriculture and the city’s defense. (Conclusions) The institute not only continued its research on hydrophobic soils and the theory of water and heat transfer processes in soils, but also successfully carried out production trials of previously developed agrotechnical solutions in the Cis-Ural region. The completion of Candidate and Doctoral dissertations, together with the publication of comprehensive monographs summarizing the results of pre-war research, became an important indicator of the normalization of scientific life.