Avaldamisel

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/3352

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Nüüd näidatakse 1 - 20 41

Effectiveness of organic fertiliser from bovine carcass residues on pasture biomass yield and nutritional value: A one-year trial comparing with inorganic fertilisers
(Estonian University of Life Sciences, 2026) Teixeira, S.M.P.; Rosa, H.J.D.; Madruga, J.S.; da Silveira, M.G.; Borba, A.E.S.
The use of organic fertilisers in agricultural soil promotes sustainable agriculture and reduces the use of chemical fertilisers, which could have an economic and environmental impact. An experiment was conducted to assess the effects of inorganic vs. organic fertiliser produced from residues (dried to 97% of dry matter DM) resulting from bovine carcass cutting on pasture biomass production and nutritional value. Twenty-five plots of a biodiverse pasture were ploughed, sown with Lolium perenne L. and Trifolium repens L. and randomly assigned to 5 treatments: control (no fertiliser) and chemical or organic fertiliser (100 and 200 kg N ha per year) in a Latin square experimental design. In the following year, monthly pasture samples were taken to determine chemical and nutritional analysis. Results for annual DM production showed no significant differences in quality of fertiliser, but rather in the quantity (only for chemical 200 being 16% higher than 100; p = 0.026). Regarding results for annual protein production, chemical was 12.9% higher (p = 0.005) than organic. For digestibility, there were only significant differences between quantities and not quality (200 was 3% higher than 100 for organic and 7% for chemical; p = 0.002). These results suggest that this organic fertiliser can replace chemical fertilisers in soils of grass pastures for dairy cattle without compromising DM production and grass digestibility. By reusing animal by-products, it promotes sustainability in line with circular economy principles, especially in areas with a high level of cattle production and beef industry such as the Azores and regions alike.
Soybean production potential in Estonia
(Estonian University of Life Sciences, 2026) Mölder, Christel; Talgre, Liina; Altosaar, Illimar; Loit-Harro, Evelin; Estonian University of Life Sciences. Institute of Agricultural and Environmental Sciences
Soybean is a widely cultivated protein crop globally, yet it is a novel crop in the Baltic States. The first scientific soybean trials in Estonia started in 2005. Farmers on the island of Saaremaa, where the climate is milder, tested varieties from The Czech Republic. Success led to the official soybean breeding program and the Estonian variety ‘Laulema’ was registered in 2014 along with the first cultivation recommendations. Soybean production expanded in 2015 and reached its peak in 2017, when 119.4 ha was planted. On-farm and certified seed-lot yields ranged from 176–784 kg ha⁻¹, with thousand kernel weight from 170.9–190.3 g and protein content from 35.36–37.55%. Pre-registration variety trials in Viljandimaa (2012–2013) recorded yields of 993–1516 kg ha⁻¹, while multi-year national variety trial records (METK) indicated a substantially wider range, from 693 to 3161 kg ha⁻¹. Certified seed batches were produced only in 2015, 2016 and 2018. Although soybean was grown every year until 2024, the production has subsequently declined, and the crop has not secured a stable place in crop rotations. Soybean cultivation is constrained by a short growing season, the risk of spring and autumn frosts, suboptimal soil conditions, limited availability of varieties adapted to Baltic-Nordic environments, and difficulties in multiplication of the sole local variety ‘Laulema’. Initial expectations were driven by expected climate change and rising temperatures. However, this 20-year assessment shows that the region's still insufficient temperature sums, and excessively wet harvest seasons further restrict production. Overall, while soybean holds potential in the Baltic-Nordic region, its broader adoption will depend on future climate conditions, targeted breeding efforts, and agronomic solutions.
Growth and yield of purple pakchoi (Brassica rapa var. Chinensis) under different cultivation systems and plant population densities
(Estonian University of Life Sciences, 2026) Fadilah, L.N.; Lakitan, B.; Marlina, M.; Muda, S.A.; Ria, R.P.; Gustiar, F.; Nurshanti, D.F.; Nur, T.P.
Rapid urbanization in Indonesia has converted productive agricultural land, thereby threatening national food security. Urban farming has emerged as a sustainable solution to address limited land availability. The increasing land constraints further limit the available cultivation area. Urban farming is a sustainable solution to land limitations for food needs of urban communities. Purple pakchoi (Brassica rapa var. Chinensis) is a leafy vegetable with high economic value, rich in anthocyanins, and has a short growing season; suitable for urban cultivation systems. This study aimed to evaluate the effects of different cultuvation system; conventional and floating, with different population densities on the growth and yield of purple pakchoi. The experiment was arranged using a split-plot design. Growth variables included leaf and stem parameters, while yield variables included fresh and sry weight, also water conten of plant organ. The results showed that cultivation system significantly affected the number of leaves, leaf length and width, canopy diameter, and stem thickness. Plant population density siginificantly influenced all yield parameters. Higher population density reduced individual plant weight but increased total fresh weight per pot, indicating more efficient land use. However, plant morphology including leaf characteristics was not significantly affected by either factor. The highest yield per pot was obtained under conventional system with high population density (3 plant pot-1); 88.15 g pot-1. Overall, the floating cultivation system supported comparable growth to the conventional system. These findings suggest that optimizing cultivation system and plant population density can improve productivity of purple pakchoi in urban farming system.
Formation and realization of the biological productivity potential of soft spring wheat (Triticum aestivum L.)
(Estonian University of Life Sciences, 2026) Radchenko, M.; Trotsenko, V.; Butenko, Ye.; Masyk, I.; Overchenko, V.; Hotvianska, A.; Lemishko, S.; Solohub, I.; Kolosok, I.; Kovalenko, M.; Yatsenko, V.
Study is aimed at an in-depth analysis of the biological and agronomically valuable traits of soft spring wheat varieties in combination with different seeding rates in order to determine their adaptability, productivity, and ability to form high-quality grain. The goal of the research was to analyze plant productivity, yield and grain quality from three soft spring wheat varieties and at three different seeding rates. This will allow us to assess the productivity of each of them. The following design was employed for the experimental evaluation of at direct effect of variety in relation to seeding rate (A = Variety; B = Seeding Rate): Variety: Shirokko, Grenny, Uliublena; Seeding Rates: 4,500,000; 5,000,000; 5,500,000 grains ha-1. The accumulation of vegetative mass during the growing season of spring wheat was determined by sampling two non-adjacent repetitions of 0.33 running meters from two adjacent rows, while yield was determined by collecting sheaf samples from each accounting plot. Protein and gluten contents were determined using a SapNIR 2750 infrared analyzer in accordance with DSTU 4117:2007 ‘Grain and its processed products’. The highest fresh vegetative mass of spring wheat plants was obtained at the milk ripeness stage in the Shirokko variety at a seeding rate of 5,500,000 seeds ha-1 – 2.90 kg m². The Shirokko spring wheat variety with a seeding rate of 5,500,000 seeds ha-1 ensured the highest grain yield of 5.63 t ha-1, with the highest gluten content in the study – 30.42%, and the highest protein content – 15.64%.
Internal security leadership, resilience, and immersive simulation for transforming training practice: Theoretical aspects
(Estonian University of Life Sciences, 2026) Allas, H.; Kalkis, H.
Internal security organisations across the Baltic Sea region operate in complex sociotechnical environments defined by hybrid threats, societal fragmentation, and cascading crises. These conditions place sustained cognitive, emotional, and organisational demands on personnel, challenging traditional training systems that remain focused on procedural and technical competencies. Emerging research underscores that leadership styles, organisational culture, and ergonomically designed work environments significantly influence resilience, health, and performance under stress. In parallel, European and national policy frameworks increasingly prioritise digital transformation and the adoption of innovative learning technologies within internal security education. The research question guiding this review is: How can human-centred leadership, ergonomics, and organisational culture be integrated through immersive simulations to enhance systemic resilience in internal security training? This study conducts a systematic literature review, synthesising interdisciplinary evidence related to human-centred leadership, ergonomics, organisational culture, and immersive simulation. Sources from major academic databases and policy archives published between 2015 and 2026 were analysed through a socio-technical and biosystems engineering lens to identify convergent patterns shaping resilience and training effectiveness. Findings highlight that resilience among internal security personnel emerges as a dynamic, system-level outcome rather than an individual trait. Humancentred leadership and well-designed ergonomic systems foster stronger organisational resilience, while immersive virtual and mixed-reality simulations enhance embodied learning, teamwork, and decision-making under stress. The study concludes that integrating leadership, ergonomics, and simulation within a unified, human-centred training model aligns with both Baltic regional security needs and the European agenda for digital transformation, offering a robust foundation for evidence-based reform in internal security education.
Study of finger-star disc working tools of an inter-row cultivator
(Estonian University of Life Sciences, 2026) Bulgakov, V.; Savchenko, I.; Holovach, I.; Rykhlivskyi, P.; Olt, Jüri; Ihnatiev, Yevhen; Estonian University of Life Sciences. Institute of Forestry and Engineering
This study combines laboratory force-deflection characterization, tomato transplant pull-out measurements and a descriptive field verification of an inter-row cultivator equipped with polyurethane finger-star discs. The objective was to relate finger hardness to crop mechanical resistance and thereby define a practical screening criterion for reducing crop damage. Discs with hardness values of 73, 83 and 93 Shore A were loaded at finger deflections from 0 to 50 mm. Pull-out force was measured for individual established tomato transplants at MG-44 instrument-reported relative soil-moisture readings of 18% (n = 5) and 10% (n = 7) in the 0–100 mm layer. The force–deflection relationships were linear (R2 = 1.000), and transplant pull-out force increased linearly with stem diameter (R2 = 0.991–0.994). During field operation at a working width of 4.2 m, travel speed of 1.0–2.0 m s–1 and disc working depth of 1.5–5.0 cm, complete visible destruction was observed for weeds at the white-thread stage and no visible injury to established tomato plants was recorded. These field proportions were obtained in a non-randomized engineering verification and are therefore descriptive. Within the tested range, 73, 83 and 93 Shore A discs are provisionally recommended for crops with pull-out forces of at least 10, 15 and 25 N, respectively. An Euler–Bernoulli cantilever-beam analysis explains the observed linear response and identifies the contact conditions that favour finger sliding rather than crop displacement.
The role of oilseed radish root mass in assessing the efficiency of green manuring systems
(Estonian University of Life Sciences, 2026) Tsytsiura, Y.; Zabarna, T.; Amons, S.
This study provides an integrated evaluation of oilseed radish root mass in the context of its use as a long-term green manure. Under conditions characterised by optimal hydrothermal regimes, the crop exhibited a pronounced capacity for root mass accumulation, reaching 13.28 t ha⁻¹ (2.71 t ha⁻¹ in dry matter (DM)) under spring sowing conditions and 8.03 t ha⁻¹ (1.76 t ha⁻¹ in dry matter) under summer sowing conditions. The corresponding mean root-system productivity coefficients were 1.86 and 2.49, respectively. Analysis of the biochemical composition of root residues, averaged across sowing periods, revealed relatively low nitrogen levels (1.45% DM) alongside elevated carbon content (40.29% DM). The residues were additionally characterised by elevated concentrations of crude fat (2.07% DM) and crude fibre (42.7% DM), as well as a notable presence of glucosinolates (17.79 μmoles g⁻¹ DM), with ash content averaging 6.26% DM. Statistical analysis indicated that the variability of these biochemical parameters was moderately associated with thermal conditions, with coefficients of determination ranging from 23% to 44% in relation to mean daily air temperature, whereas precipitation showed an inverse relationship (25–49%). Based on the calculated biochemical ratios, the root mass can be classified as a material with the maximum achievable fertilizer potential (kg ha-1 active ingredient) N34.7P11.6K89.8Ca11.7S16.6. At the same time, its relatively high carbon and fibre contents indicate a potentially slow mineralisation pattern. These results demonstrate that root biomass should be explicitly incorporated into assessments of green-manure efficiency, as its contribution extends beyond aboveground biomass and includes both nutrient inputs and longer-term carbon and biologically active compound inputs to the soil.
Applying appreciative inquiry in a transnational community of practice: a qualitative evaluation of knowledge exchange and contextual adaptation in farm health and safety
(Estonian University of Life Sciences, 2026) van Doorn, D.; Mattila, T.E.A.; Tapiola, T.; Meredith, D.
Agriculture remains one of the most hazardous occupations in Europe, yet the effective sharing and adaptation of farm health and safety (FHS) good practices across diverse national contexts continues to be a challenge. This study examines how the Appreciative Inquiry Model (AIM) can structure Transnational Communities of Practice (TCoP) dialogue to support knowledge exchange, critical reflection, and the contextual adaptation of FHS practices, rather than presenting new substantive FHS findings. While AIM has been applied in organisational and agricultural development contexts, its use in TCoP, where practices need to be adapted to different contexts, has not been empirically examined. A TCoP workshop was conducted with 25 representatives from 11 national CoPs. Data consisted of documentation of workshop discussions, participant feedback, and reflections from groupwork facilitators and SafeHabitus ‘Super CoP’ administrators. A team‑consensus thematic approach was applied by three researchers, with validation by workshop facilitators. The findings indicate that AIM effectively structured transnational CoP dialogue and created a positive strengths‑based environment for knowledge sharing. However, the model alone did not offer sufficient opportunity for the critical reflection required for context‑sensitive adaptation. Integrating explicit contextual‑analysis tools such as ‘if–then’ transfer scenarios and strengthening facilitator training would enhance the translation of shared practices into locally adapted interventions. The development and adaptation of good practices benefit from peer networks, but deeper co‑creation requires time and skilled facilitation. While project‑based networks can initiate transnational exchange, sustainable implementation of shared practices will require more stable institutionalised CoPs that support ongoing knowledge sharing, critical reflection, and contextual adaptation.
Assessment of plant nutrients losses during drying and granulation of poultry manure with amended with wheat straw and natural peat
(Estonian University of Life Sciences, 2026) Adamovics, A.; Plume, I.; Plume, L.
This study evaluated nitrogen (N), phosphorus (P) and potassium (K) losses during the drying and granulation of poultry manure (PM) and assessed the effectiveness of short-term thermal pre-treatment and organic amendments in improving nutrient retention. Seven 2.0 kg samples were prepared, comprising two samples of pure poultry manure, two PM mixtures containing 2.5 and 7.5% wheat straw (WS), and three PM mixtures containing 7.5, 15.0 and 22.5% natural peat (NP). The samples were dried to approximately 25% moisture content using either low-temperature drying at 24 °C or a combined drying regime consisting of pre-drying at 70 °C for 1 h followed by drying at 24 °C. The dried materials were granulated using a pellet press equipped with a 6 mm die, after which the granules were further dried to a final moisture content of 8-10%. The nutrient contents of both the raw materials and the produced granules were determined in an accredited laboratory. The drying regime significantly influenced nutrient retention. Granules produced from untreated poultry manure dried entirely at 24 °C exhibited nitrogen and phosphorus losses of 0.73 and 0.23 percentage points, respectively. Applying a 1 h pre-drying treatment at 70 °C reduced nitrogen losses to 0.32 percentage points and phosphorus losses to 0.12 percentage points. No detectable nitrogen losses were observed in granules produced from poultry manure amended with wheat straw or natural peat, except for a slight reduction in the treatment containing 22.5% peat. Phosphorus losses were eliminated in mixtures containing 7.5% wheat straw and 7.5 or 15% peat. Potassium losses were negligible in all treatments, with only a minor decrease observed in granules containing 22.5% peat. The results demonstrate that short-term high-temperature pre-drying effectively improves nutrient retention during poultry manure granulation. Incorporating wheat straw or natural peat into poultry manure further reduces nutrient losses during drying and pellet production, thereby improving the fertiliser value of the final granulated product.
Milk Production Response of Dairy Cows to Climatic Variables in a Compost-Bedded Pack Barn: A Case Study in the Brazilian Savanna (Cerrado)
(Estonian University of Life Sciences, 2026) Rosa, D.R.; Ribeiro, M.D.; Ferreira, N.C.R.; Arnhold, E.; Santos, N.I.P.; Barbari, M.; Bambi, G.; Andrade, R.R.
High temperatures, humidity, and heatwaves negatively impact dairy cattle welfare, reducing milk yield. This study evaluated the seasonal associations and trends between THI, air temperature, humidity, and milk yield in multiparous Holstein cows housed in a compost-bedded pack barn system from 2021 to 2023 was obtained from farm records. Air temperature (tair), relative humidity (RH), and the Temperature-Humidity Index (THI) were calculated. Data were analyzed quarterly using the Scott–Knott test, Pearson’s correlation, and simple linear regression. AMP was significantly higher (P < 0.01) from June to November (winter/spring). Correlation between AMP and THI was low (r = -0.02, P = 0.89). However, tair showed a moderate positive correlation (r = 0.36, P < 0.05) with the regression estimating an increase of 0.32 kg per degree Celsius. Conversely, RH was negatively correlated (r = -0.40; P < 0.05), with the model estimating a 0.05 kg decrease in milk per unit increase of RH. Although tair and RH significantly affect production, they interact with wind speed and solar radiation, influencing thermal load, contributing to a scenario of greater thermal stress. Furthermore, genetics, nutrition, and management are crucial mitigating factors. Properly managed, the CBP system provides a thermally adequate environment for dairy cows. However, the evaluated CBP system presented thresholds higher than those recommended in the literature.
Spectral behavior of Macaúba palms (Acrocomia aculeata) under different lighting conditions and phenological stages
(Estonian University of Life Sciences, 2026) Santana, L.S.; Surmani, C.L.S.; Santos, L.G. Maciel dos; Lopes, M.D.S.; da Silva, J.M.; Evaristo, A.B.; Rossi, G.; Bambi, G.
Climate change events highlighted concerns about renewable energy consumption. The Macaúba palm (Acrocomia aculeata) stands out as a palm with high potential for energy production. However, it is still in the domestication phase as an agricultural crop. Thus, integrating technologies such as remote sensing to monitor plant characteristics can contribute to understanding this crop's development. In this context, the study aimed to evaluate the spectral behavior of Macaúba (Acrocomia aculeata) under various lighting conditions and at different phenological stages. Multispectral images were obtained using a Multispectral Remotely Piloted Aircraft (RPA), with flights conducted at 8:00 AM, 12:00 PM, and 4:00 PM, and during two seasonal periods (February and June 2025). The aim was to analyze the effects of solar variation and plant development on reflectance and spectral indices. The results showed a strong influence of illumination on the spectral response, with an 80% reduction in reflectance under shade, with the red band being the most sensitive. Multitemporal analysis revealed marked decreases in the TCARI (-83.7%), OSAVI2 (-80.8%), and TCARI/OSAVI (-15.9%) indices, accompanied by a decrease in photosynthetic pigments and the onset of leaf senescence during the dry season. Conversely, the NDRE (+10.1%) and CIgreen (+24.7%) indices increased, reflecting maintenance of photosynthetic activity and the emergence of new leaves. NDVI remained stable, indicating the conservation of canopy structure. Multispectral RPAs' potential for phenological and physiological monitoring of tropical palms, emphasizing the importance of temporal and geometric standardization of acquisitions to ensure radiometric consistency. Integrating spectral data with solar parameters is an effective strategy to enhance the sustainable management of Macaúba palms.
Spatial modeling of coffee tree height and diameter using LiDAR SLAM, RGB imagery, and field measurements
(Estonian University of Life Sciences, 2026) Rubio, S.V.; Ferraz, G.A.S.; Cardozo, E.J.S.; Zavala, E.H.; de Oliveira, F.M.; Bambi, G.; Sarri, D.; Reis, G.M.; Ferraz, P.F.P.
Remote sensing has become established as a promising tool for crop management. In coffee farming, estimating canopy height and diameter is essential to characterize plant vigor, development, and uniformity. This study compared three approaches to obtain these variables: field measurements, RGB (Red, Green, Blue) imagery acquired by a Remotely Piloted Aircraft (RPA), and a handheld Light Detection and Ranging sensor (LiDAR), using geostatistics to assess spatial accuracy and agreement among methods. From three-dimensional data, surface and terrain models were derived, enabling estimation of canopy height and diameter, while geostatistics was used to characterize the spatial structure, select variogram models via cross-validation, and generate continuous maps through ordinary kriging. In pointwise comparison with field data, LiDAR showed better performance for height (R² = 0.80) than the RGB orthomosaic (R² = 0.63). For canopy diameter, LiDAR was also superior (R² = 0.79) relative to RGB imagery (R² = 0.71). At the spatial level, the comparison between kriged maps indicated greater agreement between LiDAR and field data, especially for plant height (r = 0.99), whereas RGB and field data showed lower spatial correspondence (r = 0.44). For canopy diameter, the maps derived from LiDAR and RGB showed good agreement with field data, with r = 0.88 and r = 0.83, respectively. Thus, the combination of pointwise assessment and geostatistical analysis proved suitable for comparing the studied methods and for interpreting, in an integrated manner, the estimation and spatial distribution of coffee tree height and canopy diameter.
Relationships between air relative humidity and soil temperature in open-field tomato production
(Estonian University of Life Sciences, 2026) Dallev, M.; Hristova, G.
Understanding microclimatic interactions between atmospheric and soil parameters is essential for precision agriculture and irrigation management. The present study evaluated the relationships between air temperature, relative humidity, soil temperature, and soil moisture under open-field tomato production using a portable ESP32-based monitoring system. Measurements were conducted at ten field points with three replicates per point (n = 30). Descriptive statistics indicated relatively stable environmental conditions during the observation period. Pearson correlation analysis revealed a statistically significant inverse relationship between air relative humidity and soil temperature (r = -0.376, p = 0.040), while no significant linear relationships were observed between the remaining variables (p > 0.05). Linear regression analysis confirmed that increasing air relative humidity was associated with decreasing soil temperature (R² = 0.142, p = 0.040), although the explanatory power of the model remained limited. Validation against a Meteobot® reference weather station demonstrated high accuracy of soil temperature measurements (relative error 0.74%) and acceptable performance for soil moisture (6.28%). The results indicate that low-cost IoT-based monitoring systems can reliably capture microclimatic interactions under field conditions and support their application in precision agriculture.
Sex ratio of offspring in turkeys with different genotypes
(Estonian University of Life Sciences, 2026) Badalyan, M.V.; Aloyan, T.B.; Markosyan, T.H.; Sargsyan, Kh.V.; Sargsyan, T.А.; Hakobyan, V.L.; Elbakyan, H.L.; Kharatyan, S.A.
Artificial regulation of the sex ratio in poultry is a critical component of intensive livestock production. It is obvious that the sex of a bird is determined not only by genetic factors but also by a number of other factors, which greatly complicates the introduction of any desired changes in the sex ratio and the solution of tasks that have significant scientific and industrial importance. The article presents results on the formation of androgenesis (male sex development) and gynogenesis (female sex development) in turkeys, due to genotype. The results demonstrate that the sex ratio in progeny significantly varies depending on parental genotype and genotype frequency. Specifically, turkeys with genotypes TfCC CpBC HbBC and TfCC Cp – HbBC produced predominantly male offspring (78% and 69%, respectively). Conversely, genotypes TfAA CpCD HbAB and TfBD CpCD HbAA resulted in predominantly female offspring (65%). In contrast, turkeys with genotypes TfAB CpBD HbCC, TfBC CpAB HbBD, and TfCD CpCC HbCD exhibited a balanced sex ratio in their offspring (P < 0.05). These findings highlight the potential use of genotype-based sex prediction as a genetic marker tool in turkey selection and breeding programs, offering a valuable approach for optimizing productivity in commercial poultry farming.
Analysis of the possibilities of using sawdust for bedding in poultry farms: A case study from eastern Poland
(Estonian University of Life Sciences, 2026) Gaworski, M.; Puszkarski, M.
The aim of the research study was to analyze the use of sawdust for poultry maintenance, from the perspective of a sawmill planning a possible expansion of its activities to include the preparation and distribution of sawdust bedding. The aim of the study became a prerequisite for proposing a test method that accounts for a diagnostic survey using a questionnaire addressed to owners of poultry farms within the potential distribution range of the sawdust producer. As a result of the study, the scale of poultry production on farms, the current mulching methods, and the actual consumption of bedding material were learned. An attempt was made to determine whether farmers are considering introducing sawdust into poultry houses, what concerns and limitations affect their decisions, and what conditions would need to be met to switch to sawdust as bedding in poultry houses. Expectations regarding the purchase and logistics service, including the preferred form of delivery, frequency of orders, and the way of handling used bedding, which affect the profitability of sawdust distribution by the sawmill to poultry farms, were examined.
Tomato growth, nutrient dynamics and yield in response to a fermented grass-based liquid fertilizer in peat-based substrate
(Estonian University of Life Sciences, 2026) Karlsons, A.; Osvalde, A.; Āboliņa, L.
Sustainable horticultural production increasingly relies on renewable nutrient sources in order to reduce the use of conventional mineral fertilizers. Fermented grass biomass can be used to produce liquid fertilizers suitable for greenhouse tomato cultivation; however, their effects on nutrient availability and crop performance in peat-based substrates are still insufficiently understood. The aim of this study was to evaluate the effects of a grass-derived liquid fertilizer, applied at increasing rates, in comparison with conventional mineral fertilization on plant growth, nutrient dynamics and yield of tomato (Solanum lycopersicum L., cv. ‘Betalux’). The experiment included a conventional mineral fertilization control and four liquid fertilizer treatments (T1–T4). Nutrient concentrations in the substrate and plant leaves were monitored throughout the growing season, together with yield parameters and the SPAD chlorophyll index. Conventional fertilization resulted in the highest total yield (1545.6 g plant⁻¹), fruit number (40 fruits plant⁻¹) and a stable nutrient status. Among the liquid fertilizer treatments, T3 performed best, producing 1,224.4 g plant⁻¹ and 35.3 fruits plant⁻¹, corresponding to a 21% yield reduction compared with the mineral control, while mean fruit weight was only moderately lower. Lower application rates (T1 and T2) resulted in progressive depletion of nitrogen, phosphorus, calcium, magnesium, iron and boron in plant tissues and led to 25–27% lower yields. In contrast, excessive application of liquid fertilizer (T4) caused substrate acidification and elevated electrical conductivity, resulting in salt accumulation, impaired nutrient uptake and the lowest yield (798.1 g plant⁻¹), despite producing the largest fruits (42.85 ± 2.06 g). Molybdenum uptake was strongly influenced by substrate pH rather than by total Mo content, whereas zinc, copper and manganese concentrations remained relatively stable. Overall, the results indicate that grassderived liquid fertilizers can support tomato nutrition in peat-based systems only within a limited application range. Careful dose management or partial supplementation is required to avoid nutrient deficiencies at low application rates and salinity-induced yield losses at excessive rates.
Evaluation of drying techniques to preserve bioactive compounds in spruce sprouts during storage
(Estonian University of Life Sciences, 2026) Karklina, K.; Ozola, L.
Spruce sprouts are a rich source of vitamins and antioxidants. Still, there is little information about the stability of compounds in different dried spruce sprouts during storage. This study aims to analyse the optimal drying method for spruce sprouts to ensure higher bioactive compound content for a shelf life of one year. Four types of spruce sprouts were analysed – fresh, dried at 40 °C, at 60 °C, and freeze-dried. Spruce sprouts were analysed for moisture, Vitamin C content, total tannin content, a-, and b- chlorophyll, total chlorophyll and total carotenoids, as well as volatile compounds in different spruce sprouts were characterised. To evaluate the optimal drying method for preserving bioactive compounds for over a year, the technique for order of preference by similarity to an ideal solution, TOPSIS, was used. According to TOPSIS, the most optimal results were observed in fresh samples. However, when analysing drying methods, the most optimal for spruce sprouts were freeze-drying and drying at 40 °C. Characterising volatile compounds in different processed spruce sprouts, regardless of the drying method, D-limonene was present at the highest concentration in all spruce sprout samples, imparting a characteristic citrus aroma. Overall, the results indicate that while fresh spruce sprouts initially contained higher levels of bioactive compounds, freeze-drying proved to be the most effective method for preserving these compounds during a year of storage. This method not only ensures long-term stability but also offers a promising approach for developing stable, nutrientrich spruce sprout products with extended shelf life and high functional value suitable for industrial applications.
Analysis and synthesis of controlled object motion in fluid via flutter interactions
(Estonian University of Life Sciences, 2026) Beresnevich, V.; Viba, J.; Vutukuru, S.; Irbe, M.; Kovals, E.; Eiduks, M.
This paper investigates the controlled motion of an object in a fluid (air or water) under conditions where fluid-object interaction occurs simultaneously at infinitely many points. An analytical framework is developed to derive second-order ordinary differential equations with constant coefficients describing object motion in a continuous medium. The approach is applicable to the analysis and synthesis of motion in fluids in the context of agricultural engineering, including the study of biological locomotion, the design and control of robotic systems operating in air or water, and the optimization of object trajectories under prescribed interactions and constraints relevant to agricultural environments. The method is based on the differential form of the momentum balance in classical mechanics and employs simplified representations of fluid-object interaction, including normal pressure effects on the object surface and experimentally determined characteristics of the suction region, while neglecting viscous forces. The applicability of the framework is demonstrated through representative cases involving fixed, translating, and rotating wings in stationary and moving fluids, as well as coplanar motions relevant to flying mechanisms. Example problems include gliding, vertical take-off, free fall, and controlled motion in a vertical plane. The results show that the proposed approach enables effective modelling of simplified object dynamics in air or water by reducing complex space-time interaction problems to systems of ordinary differential equations with specified initial conditions. The advantages and limitations of the method are discussed, confirming its suitability for analytical studies of controlled motion in continuous media.
Three-dimensional reconstruction of the trunk volume of dairy cows using RGB-D images obtained by UAV for body mass prediction
(Estonian University of Life Sciences, 2026) Oliveira, F.M.; Ferraz, G.A.e.S.; Campos, L.L.; Reis, G.M.; Cecchin, D.; Becciolini, V.; Bambi, G.; Ferraz, P.F.P.
Accurate estimation of body mass (BM) in dairy cattle is essential for nutritional management, productivity monitoring, and animal welfare. In this context, three-dimensional (3D) morphometric descriptors derived from remote sensing technologies have emerged as promising alternatives to conventional weighing methods. This study proposes and evaluates a methodological framework for reconstructing the dorsal trunk volume of dairy cows using RGB-D data acquired by an unmanned aerial vehicle (UAV). Data were collected on a commercial dairy farm under a tie-stall system, with animals moving along a defined pathway after milking, enabling standardized overhead image acquisition. Top-view images were obtained using an Intel RealSense D435i depth camera mounted on a UAV platform (3DR Solo). Point clouds were generated and processed in CloudCompare, including dorsal surface segmentation, normal estimation, and volumetric mesh reconstruction using Poisson surface reconstruction. Only closed and geometrically consistent meshes were retained for analysis. The dataset comprised 25 dairy cows, resulting in 25 observations, with BM ranging from 500 to 750 kg, stratified into 50 kg intervals. Correlation analyses showed strong positive associations between reconstructed dorsal volume and BM, both globally (r = 0.979; ρ = 0.989) and across classes. A simple linear regression model, evaluated using a 70/30 train–test split and leave-one-out cross-validation, demonstrated high predictive performance (R² = 0.967 training; R² = 0.931 testing). These results confirm the technical feasibility and zootechnical relevance of UAV-based RGB-D acquisition combined with 3D reconstruction for non-invasive BM estimation in dairy cattle, highlighting its applicability in precision livestock farming systems.
Prediction of body mass in dairy cows using LiDAR technology
(Estonian University of Life Sciences, 2026) Mancini, S.; Ferraz, G.A.S.; de Oliveira, F.M.; Rubio, S.V.; Cecchin, D.; Reis, G.M.; Conti, L.; Becciolini, V.; Ferraz, P.F.P.
Precision livestock farming has driven the search for technological solutions that enable remote and non-invasive monitoring of animal health and zootechnical performance. This study aimed to investigate the use of computer vision for predicting body mass (BM) in a herd of Holstein Friesian dairy cows using three-dimensional images acquired via LiDAR (Light Detection and Ranging). From these images, the individual body volume (BV) of each animal was digitally estimated. Subsequently, the correlation between LiDAR-derived BV and body mass measured using the conventional weighing method was evaluated. Based on this relationship, statistical regression models were fitted to predict BM from BV. The results showed that BV measured using LiDAR achieved a coefficient of determination (R²) of 0.7861 and a mean absolute percentage error (MAPE) of 4.43%. These findings demonstrate the feasibility of LiDAR technology as an effective, non-invasive alternative tool for estimating bovine body mass. The use of LiDAR enabled detailed recording of morphological characteristics and measurements, allowing continuous monitoring of body development without the need for direct animal handling. In conclusion, the incorporation of computer vision systems into dairy cattle management can optimize operational efficiency, reduce labor requirements, and promote a more sustainable production system, while enhancing animal welfare through automated monitoring.

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