Potato (Solanum tuberosum L.) is mostly suitable for growing in moderate climate conditions at temperature 20 ° C. Yields are influenced by many factors: soil characterization, available nutrients, distribution of pests and weeds, agrotechnology, genotype or variety and climatic conditions during the vegetation period. In recent years summary of meteorological conditions (precipitation and air temperature), showed that stressful conditions during the vegetation period had a diverse influence on the growth and development of plants.  Excess or lack of humidity in soil or drought and heat affected the size and shape of the potato tubers. The heat stress is the problem of agriculture in many regions of the world in the last years. The aim of the study was to evaluate cultivars and clones from the breeding material under the stress conditions at the Stende Research Centre. The field trials were set up due to project of the Latvian Ministry of Agriculture: "Evaluation of breeding material to implement integrated and organic agriculture crop production technologies"(2015-2018). The article summarizes results of nine potato clones and nine varieties in both integrated and organic systems during 2017-2018, when 2018 was one of the driest and hottest in the last 100 years. The evaluation of the varieties and breeding material phenological phases in two years showed that germination and flowering differed from year to year.  Due to hot and dry weather conditions flowering was weak for several varieties and the bud flowering was observed. In 2018 germination for some varieties was slower compared to the previous year, but for many varieties (‘Lenora’, ‘Prelma’, ‘Imanta’) and breeding material germination was not delayed (Table 1). The earlyest germination and flowering were observed for variety 'Monta'. Earlier germination compared to other varieties and clones was recorded to S01085-21 and S03067-33 and the variety ‘Rigonda’.  In the organic field earlier germination was observed for the varieties 'Rigonda', 'Monta', 'Prelma' and clones S01085-21, S07169 -35. The yield of varieties and breeding material lines in both years was good but still lower tuber yields were obtained in the integrated growing system and only one line (S01085-21) and variete ‘Gundega’ had significantly higher yield in comparison 2017. In the organic growing system tuber yields of all varieties and breeding material lines were significantly lower than the 2017 year. Yield reduction is not significant for 3 breeding material lines: S10063-128, 19922.29 and S2008-6.5.

Aim of this study is to develop a method for automatic shallow drainage ditch generation to drain terrain depressions using four factor least cost surface which is obtained using LiDAR (light detection and ranging) data and Sentinel-2 multispectral satellite imagery. LiDAR data are used for depression mapping in DEM, flow accumulation and slope modelling as well as CHM (canopy height model) to obtain relative vegetation height. Sentinel-2 imagery was used for land cover type identification as well as separating coniferous and deciduous forest stands. Study area is located in western Latvia and is 25 km2 large. Least cost surface connects DEM depressions and already existing drainage ditches by best possible path for shallow ditch network digging. Different methods are applied to determine depressions which can be drained as well as changes of affected drained area and depression depth. This results in suitable areas where to create shallow ditches to improve water runoff. Results show that using this method average reduction of area of depressions is 79% and average length of shallow ditches on each drained depression hectare is 370 m.

Rumen is a complex ecosystem where feed consumed by animals is digested by the help of rumen protozoa. They plays an important role in contributing nutrients to the host animal. This study aimed to investigate the effects of dietary inclusion of unicellular microalgae Chlorella vulgaris spp. on total count and generic composition of protozoa in cows rumen. In this study, dietary treatments were tested during three 21-d experimental periods. Each of period content different amount of microalgae supplement. In the first experimental period in cows feed was added 30g (3,14g/kg of DM) of Chlorella, in second period-90g (9,6g/kg of DM) of Chlorella and in third period-170g (18,7 g/kg of DM). As a result of this study, ciliates of 10 genera were detected and identified. The number of this genera and total amount of ciliates were counted. The analysis of rumen protozoa population in tested cows shows visible effect of the presence of microalgae in cows dietary. In particular, the density of ciliates protozoa of the cows treated with 90 and 170 g of algal supplement was visibly higher compare to results from the control diet. Microalgae-based supplement diet had stimulative effect on ruminal protozoa population and caused increasing of many protozoa genera such as Isotricha, Dasytricha, Charonina, Buetschlia, Ostracodinium, Ophryoscolex.

Since 1999, a long-term field experiment has been done at the Experimental Station of Vytautas Magnus University (former Aleksandras Stulginskis University) at 54º52′50 N latitude and 23º49′41 E longitude. The soil of the experiment site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) according to WRB (2014). The objective of our investigations was to assess the long-term impact of reduced intensity tillage systems, straw and green manure combinations on productivity and economical evaluation. A short crop rotation was introduced: winter wheat, spring barley, spring rape. The results were obtained in 2000-2017. Sustainable agroecosystems are able to maintain their condition, productivity and biodiversity, as well as their integrity over time and in the context of human activity and use. The sustainability of agroecosystems is inseparable from the stability of their productivity. In order to illustrate this, we estimated crop productivity differences % from the year 2000 to 2017. In terms of crop productivity, all the tested long-term complex measures of different intensities were similar, both when comparing with average productivity that year and when estimating cumulative differences com-pared with deep ploughing.  

Investigations were carried out in the production fields of agricultural company Linas in Ringaudai eldership, Kaunas district. Spring wheat variety 'Koksa' was grown on non-damp, light loamy soil with a mobile phosphorus content of 173 mg kg-1 and a potassium content of 139 mg kg-1. Soil acidity - pH 6.9-7.0. The ozonator was attached on the trailing sprayer JARMET. During the studies, the concentration of ozone-saturated water and the spray rate were determined so as not to damage the crop, pollute the environment, or harm humans or animals. The speed of the sprayer was 6 km h-1. The application was performed 2 or 4 times. It was determined that treatment of spring wheat with ozonated water, although not always statistically significantly, however, reduced the occurrence of powdery mildew (Blumeria graminis), brown rust (Puccinia recondita), and inhibited the spread of aphids. A tendency for tan spot (Pyrenophora tritici repentis) and thrips decrease in the crop was observed. The aim of the study was to determine the effect of ozonated water application on the spread of spring wheat pests and leaf diseases.

The success of the forest regeneration with planting is determined by many factors and one of them is soil preparation. Chosen soil preparation method impacts different environmental aspects and one of them is soil temperature and that is one of main abiotic factors determining the growth of roots.   Development of the root system is a key prerequisite for growth of newly planted trees. The aim of this research was to assess the impact of the soil preparation method on the surface (5 and 20 cm) temperature of the soil. The study was done in 8 young stand sites with different soil preparation methods, soil preparation design (orientation relative to cardinal points) and different forest types in central and north-western part of Latvia. Soil temperature measurements were taken at 5 cm and 20 cm depths in both sides of furrows and in spot mounds at every study site with hand held thermometer, in few young stands unprepared soil temperature was also measured. Mean values and standard error were calculated and the statistical significance was determined by:  the Shapiro-Wilk normality test, the Kruskal-Wallis Test and pairwise Wilcoxon test with a 95% confidence level. Our results show that soil preparation positively impact soil temperature compared to unprepared soil and soil temperature in spot mounds was significantly higher than in furrows during clear and hot (27-32°C) day at both depth and in overcast weather with moderate air temperature (20-23°C) in depth of 20 cm.

Enhanced forest growth may respond to the increasing demand for wood resources. Moreover, the forest is considered to be carbon storage, thus contributing to climate change mitigation. The forest soil fertilization, as well as forest drainage, thinning and regeneration may be an effective measure in increasing harvest rates. In the context of bio-economy, wood ash needs to be managed and can be utilized as an equivalent to potassium and phosphorus containing fertilizer. Ammonium nitrate can be used as fertilizer in forests on mineral soil since nitrogen is considered to be a tree growth limiting element in boreal forests. However, environmental aspects like leaching of the fertilizer should be taken into account. The aim of this research is to evaluate the impact of wood ash, ammonium nitrate and combined wood ash and nitrogen fertilizer impact on the chemical properties of soil water in dominated forest site types in Latvia. The trials were conducted in total in 16 forest stands. The fertilizers were spread in treatment plots, but the control plots were left untreated. The soil water samples were collected for two seasons. The pH, potassium, calcium, magnesium, phosphate and total nitrogen were determined in the soil water samples. Ammonium nitrate had an impact on the elevated concentration of total nitrogen in all experimental objects; although the significant differences between the control plot and treated plot were detected only in a part of experimental objects. The elevated concentrations of total nitrogen decreased after two months and remained above the control level. Interestingly, we observed a trend of both – increased and decreased concentrations of potassium, calcium, magnesium and phosphate. Nevertheless, only a part of the differences was statistically significant. The impact of wood ash on chemical properties of soil water was less pronounced in comparison to ammonium nitrate.

Human living conditions are the opportunity to meet his everyday needs in the field of housing, trade, gastronomy, living services, health care, education, culture, leisure. In order to offer a new perspective on living conditions, we have linked them to rural social infrastructure. The purpose of the article is to present of the ways of defining the concept of living conditions indicated in the literature. To achieve the main goal, the following research tasks were formulated: (1) to indicate of similarities between definitions and different elements (2) propose a new approach to defining living conditions (from a local point of view, for rural areas). These questions guide our research work in order to gain a better understanding about how living conditions in rural areas develop. The main research methods were used: analysis and generalization of scientific literature and documents, abstraction method, logical and systematical reasoning, graphic presentation of comparison, abstracts and other methods. The research results disclosed that the living conditions could be highly affected by other spheres of life; highly diverse requires considering the subjective perceptions and assessments of the people who live and work in these rural area. A new approach to defining living conditions in rural areas is to relate living conditions to the social infrastructure.

This paper analyses and compares regional food systems in Latvia and Lithuania from the perspective of sustainable food security and poses three questions: (i) what are the general food system characteristics and drivers of change in Latvia and Lithuania? (ii) how are the regional food systems constructed and performing? (iii) what are the conditions and pathways for regional food systems to become more sustainable?  The paper examines in-depth the food systems in two regions – Pierīga region in Latvia and Vilnius region in Lithuania. The research is carried out within the framework of the EU projects TRANSMANGO and SALSA, and the Latvian Council of Sciences project SINFO. We find that food chain concentration and the interests of big food industries and retailers drive food systems in Latvia and Lithuania while civic and consumer-driven initiatives are becoming more important in stimulating a transition towards sustainable diets. The regional food systems are a complex intertwinement between the agro-industrial, proximity, domestic, and ecological subsystems. The pathways towards more sustainable regional food systems are difficult to negotiate and enforce as they require collaboration among various stakeholders who have different agendas. The long-term prospects of the regional food systems in terms of social and economic sustainability cannot be viewed in isolation from the demographic trends in the region, the steady depopulation in rural areas and efforts in strengthening urban-rural synergies.

Field experiments were carried out at the Experimental Station of Vytautas Magnus University (54º52′ N, 23º49′ E) in Lithuania. Winter wheat was grown on the background of N150P90K90 mineral fertilization and was additionally foliar-fertilized with different concentrations of amino acid solutions (0.5-3.0%) at stem elongation and heading stages. The study was aimed to establish protein content as well as quantitative and qualitative distribution of amino acids in winter wheat grain as influenced by fertilization with different concentrations of amino acids. Experimental evidence showed that solutions with different concentrations of amino acids applied at winter wheat stem elongation and heading stages increased grain protein content and total amino acids contents. Plants, fertilized with amino acids solutions at stem elongation stage accumulated higher protein content by on average 4.8%, at heading stage by 4.5% compared with the grain protein content of plants that had not received amino acids fertilization. The total amino acids content in winter wheat grain in response to amino acids applied at stem elongation stage increased by on average 2.0 g kg-1, at heading stage by 5.3 g kg-1. Nonessential and essential amino acids content in winter wheat grain was significantly increased by 2.5 and 3.0% amino acids solutions, applied at stem elongation stage by 0.5, 1.0, 1.5% amino acids solutions applied at heading stage. Winter wheat fertilization with amino acids solutions at stem elongation stage mostly increased the content of glutamic acid, at heading stage mostly increased the contents of glutamic, aspartic, valine, isoleucine, leucine, phenylalanine, methionine, threonine and lysine acids.