The effects of different climatic conditions on birch (Betula pendula Roth) and poplar (Populus) hybrids seedlings were studied. This study consists of two parts, firstly, an experiment with poplars and, secondly, the experiment with birch seedlings. The aim of this study was to evaluate the growth of birch and poplar seedlings under the current and modelled climatic conditions. Results showed that the simulation of short-term warmer weather conditions and higher CO2 concentration led to more intensive growth of silver birch saplings. Different climatic conditions did not significantly change photosynthetic and transpiration rate of one year old silver birch seedlings. Contrary the transpiration and photosynthesis rate of poplar seedlings significantly depended on drought and clone but not on hybrid. Drought altered the transpiration and photosynthesis intensity, water use efficiency, and correlation among most of the traits. The P. maximowiczii × P. trichocarpa, P. balsamifera × P. trichocarpa hybrids increased their water use efficiency under the drought conditions and were characterized by faster growth hybrids. The sensitivity of poplar hybrids to UV-B radiation varied and depended on the origin of their parental trees: poplar hybrids from the northern latitudes were more sensitive to the increased UV-B radiation than those of southern origin. The best growth after simulated warm winter was obtained for the P. deltoides × P. nigra and P. nigra × P. nigra hybrids, originating from the southern areas. The findings from this experiment are more applicable to young birch and poplar trees, but stress on young trees may be reflected in future tree growth.

Fresh hardy kiwifruit (Actinidia kolomikta (Maxim. & Rupr.) Maxim.) possible to store for only two weeks at 0–5°C, therefore in order to maintain longer, the fruit have to be processed. The purpose of the study was to determine the quality of the Actinidia kolomikta fruit using research methods that are faster and easier, i.e. bioelectric Vincent method and biocrystallization. Four cultivars of Actinidia kolomikta fruits – ‘Landė’, ‘Paukštės Šakarva’, ‘Laiba’ and ‘Lankė’ – were investigated. Fresh, frozen and freeze-dried fruit were analysed. The amount of dry matter was determined by drying the samples to constant mass at 105 ºC, ascorbic acid was determined by titration with 2,6-dichlorphenol-indophenol sodium salt dehydrate. The pH and redox potential were measured by 781 pH/Ion Meter, electrical conductivity was measured by conductometer. P value as combined parameter was calculated according to the formula. Biocrystallization studies were carried out with fresh, frozen and freeze-dried fruits of all cultivars. The images derived from the encoded by sort samples were characterised with respect to the visual strength of form expression and were described by 10 criteria, criteria were evaluated using a 5-point scale. Research results showed that the dry matter and ascorbic acid content of A. kolomikta fruit significantly depended on the cultivar. Dry matter content of frozen fruit decreased from 4 to 7%, but increased during freeze-drying process by 6 to 7 times compare to the fresh fruit. Fruit processing methods increased pH, redox potential and P values. The lowest redox potential and P values were determined for fresh fruit, medium for freeze-dried and the highest for frozen fruit samples.

Nowadays it is paramount to promote bioenergy for climate protection, energy security and creation of income/jobs. In this perspective, Anaerobic Digestion (AD) for biogas and digestate production seems to be a viable way to simultaneously improve waste management while producing Renewable Energy Sources (RES). The main objective of this work is to assess the environmental impact associated with biomethane and digestate production from an AD plant as Global Warming Potential, expressed in CO2 equivalents. Therefore, a LCA was carried out for the production of biomethane ready for the injection into the Italian distribution natural gas grid. A mix from different waste sources (cattle manure and slurry, pig slurry, Citrus industry by-product, chicken manure, manure from broilers, triticale silage and waste from vegetable cleaning) is considered for biogas and digestate production. Besides biomethane this plant will produce digestate, that is a biological and nutrient-rich fertiliser. Thus, the cycle of circular economy is closed, as the recovery of matter and energy is carried out from waste. The results clearly indicate the importance of the process steps transport of biomass to AD plant and, above all, methane upgrading (separation by membrane). Depending on the high amount of the substrate and long distance travelled, Citrus waste substrate transport accounts for the largest share in GHG emissions with 0.229 kg CO2-eq/Nm3 or 70.5 % of total transportation emission. Greenhouse gas emissions estimated for the various process stages for the Sclafani Bagni plant showed, that methane upgrading emits 1.95 kg CO2-eq/Nm3, while other processes totally emits 0.525 kg CO2-eq/Nm3. The LCIA results confirmed the negative total impact of the process with grid injection, in terms of kg of CO2 eq.: the LCA verified the carbon-negative-bio-energy concept of the project. Therefore, biomethane derived from biogas is an entirely renewable and readily available low carbon alternative fuel, that can be locally produced from organic waste and capable to replace the fossil natural gas in the near future.

National forest inventory (NFI) is an efficient way to monitor forest resources, including increment, mortality, and harvest rate. It provides accurate statistical information about land use data, land use change and biomass stock change and enables to tie the specific increment, mortality and harvest data to defined land use category, dominant tree species, site types etc. Recently there have been introduced changes in land use calculation method using NFI data in Latvia. New calculation method takes into account present land use data and land use data from two previous cycles considerably reducing uncertainty of the estimates and takes into account possible land management practices which may alter the land use category in long-term, also usage of auxiliary data has been introduced to increase accuracy of determination of final land-use category. Changes in land use calculation method directly affects distribution of data on increment, morality and harvests between land use categories. The aim of the study is to determine increment, mortality and harvest rate in Latvia between the first and third NFI cycle (2004-2018) using updated land use data and to compare obtained result with data from the most recent greenhouse gas (GHG) inventory report.

Soil compaction is the compression of soil particles in a lower volume as a consequence of the reduction of the spaces existing among the particles themselves. This phenomenon is caused by natural forces and, above all, human ones. In order to estimate the field damages that can be caused by the traffic of agricultural machines, the load and the mean pressure applied by the tyres onto the soil can be measured. The research aim is to determine the pressure applied by each considered tractor onto the soil, in order to evaluate the effect of the traffic of tractors onto the soil itself. A total of 783 wheeled tractors manufactured and marketed in the last 35 years (1979-2014) were investigated. Data like construction year, manufacturer, model, power, total weight, weight (load) on the front and rear axle, wheelbase, front and rear type of tyres, as well as the tyre specifications, were collected. The mean pressure applied by each tractor onto the soil was computed by dividing the load applied on each tyre by its contact area. In order to reduce the pressure applied by agricultural machines onto the soil, the vehicle mass and, therefore weight, has to be reduced, or the tyre contact area on the soil has to be increased. Farmers can easily increase the tyre contact area, by decreasing the tyre inflation pressure or increasing the tyre width, i.e. mounting tyres having a larger section width, or Terra Tyres, or twin-tyres. Over the last 40 years: the mean power of mechanical four wheel drive (MFWD) tractors and four wheel drive (4WD) (isodiametric tyres) tractors increased, while that of two wheel drive (2WD) tractors remained constant; the power and the total weight increased, while the weight-power ratio decreased. Practically the reduction of the mean pressure on the soil resulted rather limited, meaning that tractor manufacturers have not bore in mind soil compaction.

EU countries agreed upon increasing the use of renewable energy, which strongly stimulates usage of biofuels. Biomass ash is generated as a residue product in large volumes as a result of biomass combustion. Heavy metal content in the ashes is the main hinder for further ash utilization in agriculture, forestry and construction sector. Aim of this study was to assess potential of biomass ash to be used as pavement base, also to evaluate risks associated with heavy metals contained in ash as well as their leaching possibility. Ash elemental analysis showed that biomass was burned efficiently, and organic carbon content in ash samples was below 2%. The limiting trace element was cadmium, which concentration in ash exceeded maximum permissible value, restricting ash recycling in forestry or agriculture. Leaching test showed that there is no threat to the environment when such waste material is used in road construction as base layer. All leaching values were below permissible concentrations or even below ICP detection limits. Compaction tests of layers made from gravel/ash mixtures revealed that biomass ash could be successfully used in road construction industry. Results showed that the strongest mixed layer was from 80% gravel and 20% ash. The compaction of this mixture was the highest, only the second best result showed pure 100% gravel, while the least compacted was 50% ash and 50% gravel mixture.

Many abandoned (term "hostless" by 2010) hydraulic structures have been exploited for over 30 years, so due to the aging of materials, the probability of failures and accidents increases. Due to the insufficient exploitation in several dams the breakdowns occurred, some ponds in damaged dams have been emptied. It is known that no comprehensive research on technical state evaluation of abandoned hydraulic structures in Lithuania has been carried out. It becomes clear that practical, scientifically based algorithms for the technical state evaluation of abandoned hydraulic structures are needed in order to assess the impact of environmental factors on the technical state, safety, reliability and durability of structures. This paper focuses on the presentation of investigation results of technical state evaluation of 4 abandoned hydroschemes in Raseiniai distr. Due to the noticed significant defects and deteriorations all 4 hydroschemes are in critical state, the pond in Gyliai IV is emptied, the demolition of reinforced concrete structures should be applied in this object.

The broadbean seed beetle (Bruchus rufimanus) is a significant pest of faba bean (Vicia faba) both in Latvia and in many other parts of the world. The objective of this study was to check the susceptibility of the faba bean variety ‘Merkurʼ to the broadbean seed beetle in Latvia, comparing it with other popular varieties: ‘Boxerʼ and ‘Lauraʼ. The trials were conducted in 2021 and 2022 at the Research and Study Farm ‘Peterlaukiʼ in Jelgava County and at a commercial farm in Cēsis County. The larval infestation rate of seeds of different varieties, the survival rate of individuals (larvae, pupae, imagines) in the seeds, as well as the percentage of seeds damaged by the pest in the yield were compared. It was observed that ‘Merkurʼ seeds were significantly less infested than ‘Boxerʼ and ‘Lauraʼ seeds. However, the survival rate of larvae in the seeds of ‘Merkurʼ was similar to that in ‘Lauraʼ seeds and higher than in ‘Boxerʼ seeds. The highest proportion of seeds damaged by the pest was found in the ‘Merkurʼ and ‘Boxerʼ yields, varying between 5–75% between years and trial locations. Therefore, it was concluded that the variety ‘Merkurʼ, evaluated from a practical point of view, does not differ from the other two varieties. Without taking additional plant protection measures, the percentage of seeds damaged by the broadbean seed beetle can significantly exceed the maximum limit (3%) specified in the buyersʼ quality criteria.

This article presents the results of studies on biological samples collected from 640 swabs taken from dogs and cats across various regions of the Republic of Kazakhstan. These samples were part of a monitoring study on the spread of coronavirus among domestic animals. Total RNAs were isolated using the magnetic sorption method with the ALPREP kit and subsequently analysed with the ALSENSE-SARS-CoV-2 RT-qPCR kit. Real-time RT-PCR analysis revealed that 104 samples tested positive within 22–37 amplification cycles. These positive samples were then cultured in Vero cell lines to confirm the presence of the virus. The biological activity of the resulting virus-containing suspension was determined using the Reed-Muench method. During cultivation, one viral isolate with a biological activity of 5.83±0.08 lg TCID50/ml was obtained. A microphotograph of the virus was taken using an electron microscope to determine its size, shape, and structure, which confirmed its morphology corresponding to the Coronaviridae family. The data obtained further indicate that domestic animals can suffer from and carry coronavirus. It is becoming increasingly evident that the virus can infect and replicate in the organs of various farm and domestic animals.

Light is one of the most significant environmental factors affecting the growth of plants, as it is the driving force of photosynthesis. Among others, the red and blue light are the most relevant, as these spectral regions are absorbed by chlorophyll the most. In addition, red and blue light trigger specific photomorphogenic responses that allow plants to capture the available light efficiently. Accordingly, the proportion of red and blue light (R:B ratio) is considered one of the most important characteristics of light for plants, as optimal R:B provides balanced growth and photosynthesis. The aim of this study was to evaluate how the in vitro cultures of hybrid aspen (Populus tremula L. × P. tremuloides Michx.) are affected by different R:B ratios under fixed illumination intensity. We examined the growth characteristics of plantlets under wide spectrum LED luminaires with three different R:B proportions – 1:1, 7:3 and 9:1. While photosynthesis-related variables were significantly affected by light, the effect on morphology was less pronounced. Overall, increased proportions of red light decreased the photosynthetic performance of plantlets without giving significant benefits in the form of longer shoots that could be used to facilitate propagation effectiveness. Nonetheless, the effect of light treatment remains at least partially clones-specific and should be considered in case of further application for propagation purposes.