Kvass is an aromatic soft drink which in a form of powder could be used in dairy or bakery products, or sugar confectionary to expand the diversity of flavours. Spray drying is one of the techniques used for producing powders; however, liquids with high sugar content become sticky during drying process and need additional drying aids to increase glass transition temperature and improve powder stability. The aim of this research was to evaluate the characteristics of dry naturally fermented kvass. Maltodextrin was used in 50, 40 and 25% quantity to kvass dry matter in order to aid the spray drying of naturally fermented non-pasteurised, non-filtered bread kvass. Spray drying of 8 l naturally fermented kvass returned approximately 500 g dry naturally fermented kvass powder with a light brown colour, a pronounced aroma of rye bread and moisture content of 7 ± 0.1%. Microstructure analysis of the spray dried naturally fermented kvass showed irregularly spherical shaped particles, having many shrinkages, breakages and dents on the surface in general. Total viable microorganism count in dry naturally fermented kvass powder was within the recommended levels, traces of lactic acid bacteria were found in all samples. The presence of Bacillus amyloliquefaciens was established in dry naturally fermented kvass powders, with possible contamination from spray dryer.

This study was designed with the aim to determine the impact of residual antibiotics on haematological and biochemical constituents of broiler chickens’ blood. For this, one-day-old chickens were randomly divided into four equal groups with 10 individuals in each group (n = 40). All groups of chickens fed with commercial basal diet; the first group considered as control, fed only with basal ration; the feed of the second, third and fourth groups of chicken were supplemented with amoxystin, tetracycline and chloramphenicol, respectively. Antibiotics were given daily, individually, in sub-therapeutic concentrations: amoxystin at the dosage 10 mg kgE-1, tetracycline and chloramphenicol – 20 mg kgE-1 of the chicken’s weight for 41 days. The blood parameters were measured at the end of experiment on the 42nd day. In comparison with the control group, decreasing of leukocytes was observed in the 2nd and 4th groups, and increasing in the 3rd group of broilers. The concentration of erythrocytes and hemoglobin was reduced in the 2nd group and hematocrit was higher in the 3rd and 4th groups (p is less than or equal 0.01). The total protein was decreased by 22% in the 2nd group, 16% – in the 3rd and 4th groups as compared to the control group (p is less than or equal 0.01) in blood serum. The concentration of glucose was decreased by 45.8, 46.5 and 51.5% in the second, third and fourth groups of treated birds, respectively, compared to those of birds in the control group (p is less than or equal 0.01). Based on the results it could be concluded that antibiotics influence the dynamics of haematopoiesis and biochemical indices of broilers.

Actual and reliable meteorological data are necessary for building performance analysis. Since meteorological conditions vary significantly from year to year, there is a need to create a test reference year (TRY), to represent the long-term weather conditions over a year. In this paper TRY data model was generated by analysing every 3-hour weather data for a 30-year period (1984 – 2013) in Liepāja, Latvia, provided by the Latvian Environment Geology and Meteorology Centre (LEGMC). TRY model was generated according to standard LVS EN ISO 15927-4. The generated TRY contains from typical months that are included in TRY from a number of different years. The data gathered from TRY was compared with the climate data from the Latvian Cabinet of Ministers regulation No. 379, Regulations Regarding Latvian Building Code LBN 003-15. Average monthly temperature values in LBN 003-15 were lower than the TRY values that indicate on climate changes in this location. The results of this study may be used in building energy simulations and heating-cooling load calculations for selected region. TRY selection process should include the latest meteorological observations and should be periodically renewed to reflect the long-term climate change.

This article deals with the use of the service learning method in the study courses of landscape architecture bachelor studies outcomes from a student’s perspective. This kind of research is unique with combining service learning method research and involvement of student’s perspective. The service learning method, which includes both theoretical studies and practical work in the planning of actual territories and communication with the customer, is important for the development of professional competences in the field of landscape architecture. The aim of the research was to state the benefits of students’ professional growth from using this method in the study process. The article summarises the evaluation of the experience of Latvia University of Agriculture landscape architecture studies in cooperation with 3 non-governmental organisations, 8 municipalities and governmental organisations and 4 associations from 2013 to 2016. The research was based on the students’ survey. The students had to answer close-ended questions about the knowledge they had acquired from the projects of different scales. As a result of the survey, it was concluded that the students’ main benefits of professional knowledge are mainly associated with a better understanding of specific features of particular places, which is not always possible within the framework of theoretical studies. The possibility of presenting projects to a real customer, thus improving one’s presentation skills was also positively evaluated.

Groundwater is the main drinking water source in Latvia, and Quaternary groundwater is widely used in households due to shallow occurrence. The identification of vulnerable areas is important for better water management and protection of deeper, more intensively used aquifers. The existing groundwater vulnerability map of Latvia does not take into account land use which can be an important factor affecting natural groundwater quality. Multivariate statistical methods - principal component analysis (PCA) and hierarchical cluster analysis (HCA) - were applied to identify groundwater groups with distinct water quality in Quaternary sediments in Latvia. On the basis of major ion concentrations and nitrogen compounds four distinct groundwater groups were identified. First group represents natural and most common calcium- magnesium bicarbonate water type in Latvia with low nitrate and ammonium concentrations. Samples from second and third group both reflect anthropogenic influence: diffuse agricultural contamination mostly with nitrates and/or contamination derived from artificial surfaces. Fourth group belongs to calcium bicarbonate water type and is characterised as a very young groundwater formed in sandy deposits. The results show that the highest concentrations of nitrogen compounds can be found in areas with agricultural land use or in artificial surfaces which are often classified as medium low or low vulnerability areas (mostly samples from group two and three). Meanwhile the lowest values of nitrogen compounds are present in areas where dominant land covers are forests and semi-natural areas or wetlands, and groundwater vulnerability classes are medium to high (samples from the first and fourth group).

Results of various studies show that the most prevailing risk factors on workers of agricultural sector are noise and vibration. These hazards are especially important in transportation and most field works. Results from previous studies show that vibro-acoustic environment in tractors operated in Lithuania usually cannot be attributed as acceptable, but technical solutions implemented by manufacturers had definitely positive influence on working conditions. Noise level reduced from 90 dB(A) (tractors of 1980 – 1990 years of manufacture) to 73 dB(A) (tractors manufactured from year 2000). As renewal of tractors is not sufficient, there is still a large number of old machinery i.e. noise levels might be as high as 92 dB(A) which allows to work safely only one hour per day without personal protection. It was found that values of whole body vibration (WBV) during ploughing operation might be as high as 1.5 m∙sE-2 which excess the vibration limit value of 1.15 m•sE-2, while hand-arm vibration (HAV) did not exceed the vibration action value of 2.5 m•sE-2. Significant effect of tyre pressure was noticed on vibration values measured on driver’s seat. Vibration acceleration values may be reduced to safe 0.5 m•s-2 by selecting appropriate tyre pressure.

The aim of the article is to ascertain the interaction between weather conditions and electric energy consumption in the Latvia household. The electric energy consumption data in the Saurieši village, Riga region, Latvia, for the year 2012 were collected, and the climate data for the same period including the duration of the sun-shine, ambient air temperature, precipitation intensity, and wind speed were obtained. The research hypothesis that there is strong relation between weather conditions and electric energy consumption was proved partially – there is rather strong correlation between household electric energy consumption and air temperature (r = 0.91), and medium correlation between household electric energy consumption and precipitation (r = 0.61), as well as between household electric energy consumption and duration of the sunshine (r = 0.67). Correlation found between weather conditions and electric energy consumption in the household allows to forecast the trends in energy consumption based on weather measurements, and even to use the weather forecasts for electric energy future demand trends development. The equations developed explain the household energy consumption patterns in Latvia with its geographical location and economic conditions, but the methodology developed can be applied for any region if necessary data are available.

Modern varieties developed under conventional plant breeding programs do not always perform well under organic and low-input growing conditions. Therefore, organic farmers need varieties adapted to variable environmental conditions. This means emphasis on traits such as nutrient uptake and use efficiency, good weed suppression ability and disease resistance and can be achieved via extended genetic diversity within the varieties: variety mixtures and populations of self-pollinating crops. The aim of the present study was to review published scientific literature about importance and research results on this topic. Scientific articles about the necessity of such studies and results of investigations performed in different countries have been studied. The main results show that variety mixtures have advantages in terms of disease control and yield stabilization and performance of mixtures may be affected by various factors – choice of components and its number, interactions between plants of components, manner of the mixing and growing technology. Depending on parental material, populations contain greater genetic diversity than variety mixtures. There are trends observed in the studies that yield of populations increased over generations and they are more stable than modern varieties, but there is no evidence that they would be significantly more productive. This research direction has recently become topical and is not sufficiently widely covered in the world agricultural science. The obtained results are inconsistent.

Flax (Linum usitatissimum L.) fibre and seeds are widely used to produce healthy and environmentally friendly products. It is known that the main factors that influence flax fibre’ and seeds’ yield are genotype and growing conditions. The main task of the Latvian flax breeding program is to develop flax genotypes that are highly productive (both fibre and seeds) and well adaptable to changing environmental conditions. Goal of this study is to identify high yielding genotypes with good adaptation to local variable agro-ecological conditions. The agronomically important traits, such as yield of stem and seeds, total and technical plant height and fibre content were evaluated for 13 Latvian origin flax lines and standard variety ‘Vega 2’. The field trials have been carried out over the period from 2012 to 2015 at the Agricultural Scientific Centre of Latgale. The regression, correlation, coefficient of variation and cluster analysis between yield and yield provided components were used for identification of high yielding genotypes with good adaptation. On the basis of cluster analysis the genotypes were classified in two groups by lower and higher yield of stem, fibre content, total plant height and technical plant height. The line ‘I18-1’ was identifying as genotype with the highest average yield of stem (751.25 g mE-2) as well as highest yield against other genotypes in moisture and drought years. Most valuable by the average technical plant height was line ‘L26-1’ (73.05 cm).

Since the middle of the last century rapid intensification of agricultural production systems has resulted in dramatic increase in fertilizer consumption as fertilizer has been considered as one of the most important factors for increased yields. However, not all the nutrient ions in a fertilizer applied to soil are taken up by crops, thus certain amount of the applied fertilizer is lost from agricultural fields leading to increases in nitrogen surplus, nitrogen losses to the environment and harmful impacts on biodiversity, air and water quality. This study aims to focus on crop fertilisation planning which is based on the knowledge of physical and chemical properties of soil and involves performing soil tests, designing a fertilisation plan and its practical implementation as well as calculating the balance of N, and to evaluate crop fertilisation planning as a tool for achieving balanced economic and environmental benefits in crop farming, which play an important role in efficient farming. In this study, the authors have analysed current situation in Latvia regarding requirements for fertilization planning in crop farms and have assessed potential costs and benefits from fertilisation planning. The research finds out that total cost of introducing of fertilisation planning ranges from 34 to 22 EUR haE-1, however, fertilisation planning is a neutral measure where costs are compensated by savings from N inputs which ranges from 10 to 40 kg N haE-1.Fertilisation planning generates environmental benefits, i.e. – reduces direct N2 O emissions from agricultural soils by 47 – 187 kg CO2eq haE-1 through reduced N fertilizer inputs.