Geophysical studies in mapping and screening applications are widely applied for archaeological, environmental, geological, hydrological and many other applications. Ground-penetrating radar (GPR) is one of methods from geophysical toolbox that is also called a ground-probing radar, subsurface radar, surface-penetrating radar and ‘georadar’ or impulse radar – it is a non-invasive and non-destructive technique. Pulsed electromagnetic signal is recording the reflected energy and scattering from subsurface objects. Studies were performed in former Littorina Sea lagoons that became lakes after the further Limnea Sea stage in the Baltic Sea established with comparatively lower absolute sea level that is close to present day situation. Characterization of sediments as well as full sediment core description for comparison with GPR signals were performed. Major results show that GPR as non-destructive method in combination with geological coring followed by laboratory analysis of sediment properties can be successfully used to describe layering conditions, topography and depth of shallow lakes. Although there are some limitations regarding the electromagnetic (EM) noise and similar EM properties of analysed sediments, proper treatment of data gives complementary insight thus diminishing the necessity of dense coring network establishments in analysed areas of lakes. The aim of this screening study is to analyse potential advantages of GPR use for mapping sediments and topography of sandy bottom in shallow lagoon lakes as well as pinpoint problems during field and cameral works considering electromagnetic, geological and topographical disturbances.

In this study, forest type mapping data set taken from UCI (University of California, Irvine) machine learning repository database has been classified using different machine learning algorithms including Multilayer Perceptron, k-NN, J48, Naïve Bayes, Bayes Net and KStar. In this dataset, there are 27 spectral values showing the type of three different forests (Sugi, Hinoki, mixed broadleaf). As the performance measure criteria, the classification accuracy has been used to evaluate the classifier algorithms and then to select the best method. The best classification rates have been obtained 90.43% with MLP, and 89.1013% with k-NN classifier (for k=5). As can be seen from the obtained results, the machine learning algorithms including MLP and k-NN classifier have obtained very promising results in the classification of forest type with 27 spectral features.

Due to the globalization, the financial sector has undergone major changes in the way services are provided and delivered. Customers increasingly prefer to receive services remotely, which is a more convenient and faster way, but the majority of European banks are not ready to provide it. 90% of European banks invest less than 0.5% of total spending on service digitization; therefore, only 20 – 40% of the processes are digitized. The service digitization can be a major challenge for banks in the future. Only banks that provide a full range of digitized services will be able to increase profitability and revenues and reduce costs. Therefore, it is necessary to analyse the satisfaction of international corporate customers and define the role of digitized services to improve international activities of banks. Quantitative and qualitative research methods, including the statistical data analysis, graphical analysis, linear and multiple regression analysis, correlation, comparison and grouping methods, as well as survey have been used for the research, and SPSS 20 has been used for data processing. So far there are no analyses of the digitized services in Latvia that would be based on international customer experience and needs. The results of the research concluded that the higher usefulness indicator, the higher is the possibility that international corporate customers will continue to use internet banking services. The digitized services strategy ensures the availability of essential daily digitized services in internet banking and ensures the savings in time and in financial resources for the bank and its international corporate customers.

The purpose of this study was to predict and compare salt accumulation in the soil profile under drained and undrained conditions. The water management simulation model, Drainmod (Ver. 6.1) was used to determine the optimal drainage system design parameters, which will decrease soil profile salinity and provide maximum crop yields in Ankara-Bala Basin of Turkey. Soil sampling points were coordinated with the Global Positioning System (GPS). Soil, crop and site parameters were obtained as an input. The model was run for 5 years from 2005 to 2010 to simulate optimum drainage design parameters (drain depth, drain spacing) while controlling soil salinity in the root zone. Soil water conditions and soil salinity level were simulated for crop rotation of corn (Zea mays) and winter wheat (Triticum). Yield of individual crops was predicted for each growing season. The results of the simulations were analyzed to identify alternatives of subsurface drainage system that would satisfy maximum crop productions. According to the simulation results, the drain spacing of 130 m and drain depth at 160 cm are recommended for Bala Basin. Soil salinity maps were created for undrained and drained conditions. Results showed that the soil salinity level and salinity stress can be reduced and yield increased by installing a drainage system.

Grain quality adversely affects price and consumer acceptance of finished products. Hagberg falling number (hereinafter falling number) is one of the most important grain quality indices of winter wheat (Triticum aestivum L.), especially in humid climate countries (Northern Europe). Field experiments with winter wheat cultivars ‘Bussard’ and ‘Zentos’ were conducted at the Latvia University of Agriculture, Study and Research farm ‘Peterlauki’ during a three year period (from 2009/2010 to 2011/2012). The aim of this investigation was to clarify variation of the falling number (FN) depending on cultivar, weather conditions and different rates of nitrogen (N) fertilizer applied (N 60, N 90, N 120, N 150) on fresh and stored grain (60, 120 and 360 days). During the investigation period, wheat ‘Zentos’ grain was characterised by a higher falling number compared with ‘Bussard’ grain. The falling number values for fresh grain for both wheat varieties studied were high: averagely 301 s for ‘Bussard’ and 359 s for ‘Zentos’, and reached demands set for grain suitable for bread baking. Differences in the falling number values were noted when freshly harvested winter wheat grain was compared with grain stored for 60 or 120 days and 360 days. During storage (60 – 360 days), α-amylase activity in winter wheat grain reduced and the FN increased on average up from 94 to 110 s. The falling number significantly depended on weather conditions, grain storage period and nitrogen fertilizer. The higher was the falling number of freshly harvested grain, the higher its increase during grain storage of compared to freshly harvested grain with a lower falling number value.

Pisum sativum L. (field or garden pea), is widely cultivated in Europe. The purpose of this investigation was to see whether pea varieties differ in their yield and content of protein and nutrients. Another aim was to select the best varieties suitable for breeding or production. A field experiment with different varieties of peas (‘Bruno’, ‘Capella’, ‘Clara’, ‘Mehis’ and ‘Vitra’) was carried out at the Estonian Crop Research Institute in 2014. Yields (t haE-1) were not statistically different. Crude protein content (g kgE-1 in dry matter) was lowest in ‘Clara’; all other varieties had a higher content of protein, within much the same range. The lowest N content was found in ‘Clara’, followed by ‘Capella’ and ‘Vitra‘, ‘Mehis’ (44) and the highest in ‘Bruno’ (45). The lowest P content was found in ‘Clara’, followed by ‘Capella‘ and ‘Vitra’; the highest was found in ‘Bruno’ and ‘Mehis’. The lowest K content was found in ‘Mehis’, then ‘Clara’, followed by ‘Capella’ and ‘Vitra’ and the highest in ‘Bruno’. The lowest Ca content was found in ‘Clara’, followed by ‘Capella’ and ‘Mehis’, ‘Vitra’, and highest in ‘Bruno’. The lowest Mg content was found in ‘Capella’, followed by ‘Clara’ and the highest in the other varieties ‘Bruno’, ‘Mehis’ and ‘Vitra’. Thus, choice of the right variety for pea cultivation is very important, but depends on the local agro-climatic conditions. This investigation has been developed with the help of the project EUROLEGUME, funded from the European Union Seventh Framework Programme for Research, Technological Development and Demonstration under the grant agreement no. 613781.

In Estonia, the most promising perennial grass used as raw material for production of heat energy is reed canarygrass (Phalaris arundinacea L.). Nordic countries (Finland, Sweden) implement a technology including single harvest of the above-ground biomass from frozen soil early in spring. This technology cannot be used in Estonia as the ground does not freeze to the extent of bearing harvesting machines every year. Harvesting in spring is virtually impossible as herbage lodges excessively under the snow weight. A divided harvesting method of reed canarygrass was tested in field trials in 2010–2013 at the Estonian Crop Research Institute. Herbages were cut in July at the height of 60–65 cm, mass was dried as hay, stubble hay was left to grow and was harvested next spring before the growth started but soil had become dry. The effect of seeding rate, row spacing and nitrogen fertilizer on the dry matter yield of reed canarygrass was investigated. The amount of produced heat by trial variants was calculated. The variant with narrow spacing (15 cm), seeding rate of 8 kg haE-1 and usage of fertilizer N70 in the beginning of growth and N70 kg haE-1 after the first cut was giving the best results. Two cuts of this variant yielded on average 8.12 t haE-1 per year, of which the stubble hay, harvested in spring and with better combustion properties, made 64%. Energetic value of the yield was 138 GJ haE-1 per year.

The objective of this study was to evaluate the main plant nutrient: mineral nitrogen (NH4 + -N and NO3 -N) dynamic in soil under fertilizing for obtaining high grain yields of winter wheat (Triticum aestivum L.) and to determine relationships between nutrient uptake and winter wheat productivity. The field study was carried out at the Research and Study farm ‘Vecauce’ of the Latvia University of Agriculture for two years 2012/2013 and 2013/2014 with winter wheat variety ‘Kranich’. Different nitrogen application rates (0, 85, 153, 150, 175, 180 and 187 kg haE-1) and timing were used for winter wheat. The content of nitrates NO3 -N and ammonium nitrogen NH4 -N was determined in the soil layers 0-0.20 m, 0.20-0.40 m, 0.40-0.60 m. Nitrogen management strategy during the plant growth period based on soil Nmin evaluating can improve N use efficiency and reduce environmental contamination. The maximum of mineral nitrogen content in soil in the vegetation period was observed at the beginning of stem elongation with a tendency to decrease. A significant impact (p is less than 0.05) of nitrogen fertilizer application was noted on the mineral nitrogen content in soil layer 0-0.20 m deep in both trial years. The increasing doses of nitrogen fertilizer raised the amount of mineral N in the soil profile. The significant impact (p is less than 0.001) of nitrogen application and year conditions was observed on grain yield. Close positive correlation significant at 99% probability level was observed between the grain protein content and nitrogen concentration mostly in all soil layers, but it was not found between the grain yield and nitrogen content.

Environmental conditions and climate change on a global scale affect the overall agriculture and food supply. Globe artichoke (Cynara cardunculus var. scolymus (L.) Fiori) is widely distributed all over the world. Immature inflorescence, commonly called capitula or head, is used in human consumption. These vegetables are a good source of human health promoting components. Artichokes are widely used in human diet, characterized by low protein and fat, high content of minerals, vitamins, inulin, carbohydrates and polyphenolic compounds. Relationship between plant growth and development is tight and complicated. Many agroecological factors, such as temperature, irrigation and fertilization level, planting and harvesting date, influence processes of growing and development of globe artichoke. Biologically active compounds in plants are dependent on climate conditions, seasonal changes, cultivar properties and maturity. Pre-germination is required for better plant establishment in the field. Better plant growing and development can be ensured by regular irrigation which provides 85 – 100% from evaporation and applied fertilization before planting and during vegetation period according to soil properties. The biochemical quality of artichoke heads differs between cultivars, head fraction, and stage of head development. This indicates possibility to grow artichokes in Latvia.

There is an increasing demand in the development of new and better types of organic plant fertilizers. The aim of the present study was to evaluate if the beneficial effect of vermicompost on plant growth and development could be further promoted by adding different amounts of bat guano using two model species under controlled conditions, as well as to assess the microbiological characteristics of bat guano and soil after its application. The study was performed at the Faculty of Biology, University of Latvia, during 2013 and 2014. The amount of bacteria was significantly lower in guano in comparison to vermicompost samples. No actinobacteria were present, but yeasts were found in the guano sample. Soil fungal populations after the application of organic fertilizer from vermicompost and bat guano were dominated by potentially plant growth promoting fungi Trichoderma and Mortierella. However, at increased guano concentration (300 g kg˗1) the proportion of potentially plant pathogenic fungi significantly increased. Addition of bat guano to vermicompost fertilizer significantly enhanced the positive effect of the fertilizer on growth and development of winter rye (Secale cereale L.) and potato (Solanum tuberosum L.) plants.