The aims of the study were (a) the determination of the physicochemical characteristics of properties of pellets made of shredded residue from hay, wheat straw, and their blend at a ratio of 50:50, and (b) the determination of a mathematical model of pellet durability, using a response surface method. Tests were conducted according to applicable standards. As a result of thermal changes during the pressure agglomeration process, the material moisture content of pellets had slightly decreased versus raw three biomasses by 0.50% w.b. (wet basis) to a final value within the range of 5.56–5.87% w.b. The pellet properties of the blend were not adequately represented by the arithmetic mean of their components. Pellets made of hay, straw, and their blend, had DM (DM—dry matter) specific densities of 1034, 974, and 1102 kg m⁻³, respectively. The densities showed correlation with calorific values (r = 0.637), which were in the range of 16.07–17.00 MJ kg⁻¹. The pellet durability coefficient correlated negatively with particle size and biomass moisture content. On the basis of previous conclusions, a non-linear mathematical model was formulated to account for the pellet durability coefficient relative to pellet moisture, and the relation of particle sizes and specific density to pellet bulk density.

Crop monitoring using UAVs is becoming standard practice in scientific research due to the possibility of an operational examination of large fields with high data quality due to high-resolution images. The need for operational inspection of crops on an industrial scale requires a certain balance between the permissible image quality and the acceptable monitoring time due primarily to the number of UAVs and their energy. The newest and most relevant stress factor for Ukraine is technological stresses. The aim of the study is the optimal flight altitude for monitoring stresses of a technological nature. Field studies were carried out from September to November 2019 in the Boryspil region on industrial crops of winter rape. Monitoring was carried out using the Slantrange 3p complex. Stresses were recorded according to 2 parameters - the area of the dome and the abnormal coloration of the 2 lower leaves of red, yellow, and a mixture of these colors. The maximum quality of identification is achieved at the maximum resolution of the images, that is, the minimum height, however, the issues of UAV energy determine the maximum height and, accordingly, the flight speed for the UAV. Thus, the optimal compromise is between the determination accuracy and the production-appropriate flight parameters, that is, a lot of metric optimization is needed. As a generalized criterion, the criterion of consistent products was chosen, where the number of local optimization criteria is s = 3, and the weighting coefficients of the criteria are selected subjectively by experts. The proposed algorithm for choosing the optimal UAV flight altitude to identify the technological nature of the stress of winter rape crops will allow planning monitoring activities and justifying the choice of UAV parameters relative to the duration of its flight. The type of objective function used will allow specialists without specialized education in programming to solve the problem of multi-criteria optimization by its own weight coefficients. The proposed approach has no restrictions on the number of optimization parameters and the number of local optimality criteria and can be used when the user chooses his own indication indicators.

This study investigated the effect of co-fermentation by Pediococcus acidilactici KKP 2065p and Lentilactobacillus buchneri KKP 2047p on propionic acid production and biogas yield from grass silage. The research was conducted in three stages. First, the growth dynamics and acid production of mono- and co-cultures were assessed in modified MRS media supplemented with glucose and 1,2-propanediol (1,2-PDO) under laboratory conditions. Len. buchneri monoculture produced the highest concentration of propionic acid (3.06 g/L), while co-culture with P. acidilactici yielded 2.88 g/L. In co-cultures of P. acidilactici KKP 2065p and Len. buchneri KKP 2047p, no synergistic increase in propionic acid or 1-propanol production was observed compared to monocultures. In MRS medium with 1,2-PDO, Len. buchneri primarily contributed to acetic acid synthesis, while P. acidilactici was responsible for propionic acid and propanol formation. Notably, a high concentration of 1-propanol was associated with a possible metabolic shift or intermediate accumulation. Second, silages were prepared from grass and inoculated with the selected LAB strains. Silage fermentation was evaluated through analysis, which revealed increased lactic acid content (7.30 vs. 2.83 g/kg DM in control) and a dominant presence of Lactobacillus (91.8 %) in inoculated silages, alongside a marked reduction in Weissella and Enterococcus spp. The synergism of the selected two strains significantly affected the increase in acetic acid content, which occurred more relevant in anaerobic digestion and biomethane yield in the third step when the biogas potential of the silages was assessed. Inoculated silages showed a 14-21 % increase in methane yield (up to 376 mL/g VS), with methane content reaching 46-55 % (compared to 36-45 % in the control). These results demonstrate that the combined use of P. acidilactici and L. buchneri can enhance both the volatile organic acids content in ensiled plant material and renewable energy output.