Effects of nitrogen fertilizers and weather conditions on spring barley (Hordeum vulgare L.) yield and grain quality were investigated at the Rumokai Experimental Station of the Lithuanian Institute of Agriculture in the period of 1998-2000 and 2003-2004. The soil of the experimental site was Hapli Epihypogleyic Luvisol. Analyses were made with fertilisers rates of 0 and 90 kg haE-1. The data of analyses indicated a positive and reliable correlation between the yield of spring barley and the amount of precipitation in May (rate of correlation was 0.70**) and a negative and reliable correlation with the amount of precipitation in June and July (rates of correlation were -0.80** and -0.29* respectively). A reliable though weak correlation was found between the application of nitrogen fertilisers and the yield of grains. The amount of precipitation in April and the spring barley leaf diseases had a considerable negative effect on 1000 grain weight and grain size. Strong correlation was identified between the amount of precipitation in May and June and the protein content in grain. Nitrogen fertilisers promoted protein accumulation in grain.

The vegetation pot experiment was conducted at the Institute of Soil and Plant Sciences of the Faculty of Agriculture of the Latvia University of Agriculture. The aim of the experiment was to investigate the effectiveness of five Rhizobium legumonosarum strains stored in the period from the 18th of August till the 20th of October 2006 in the collection of the Latvia University of Agriculture. Three of the five mentioned Rhizobium legumonosarum strains were included in the international Rhizobium database IBP World Catalogue of Rhizobium collections. Taking into consideration the results of the experiment it has been pointed out that all Rhizobium strains were active and inoculated plants formed nodules on the roots. Inoculation with Rhizobium strains increased the proportion between shoots and roots' weight. It has been found that the dry matter content of the inoculated plants increased in comparison with the untreated ones. In addition, negative correlation between the dry matter and the protein content has been observed.

The aim of this research is to evaluate the variability of the martagonlily (Lilium martagon L.) found in the wild in the west of Latvia. Latvia is situated in a nature zone between the vegetation of Northern and Central Europe. The country distinguishes itself with a large variety of flora and fauna (total approx. 27, 7 thousand species). The genus Lilium L. includes approximately a hundred species, subspecies and varieties of species. In northern Europe, one of the best known and longest cultivated of lilies is L. martagon L. It is distributed across the largest growing area of most species - from western Portugal throughout Europe and Asia. To evaluate the survival potential of L. Martagon L. in Latvia, research was carried out in locations at Kurzeme - districts of Ventspils, Kuldiga, and Tukums. The results indicate that the diversity in genotypes varies according to location and distribution. There are differences in phenotypes and colour variability from pale to bright violet-pink. Diameter of flower varies between of 3.5 to 6.0 cm. The height of these plants varies up to 114 - 130 cm. The flowering time is in June and July. Wild martagonlily found in these regions is growing in calcareous soils among shrubs in river valleys and semi-shaded deciduous forests. This particular martagonlily is hardy and disease resistant and is recommended as a donor in breeding programs.

A study was conducted to determine efficiency of an organic acids and phytogenic additives on pigs' growth processes and digestive tract microflora. The feed of the control group (C) did not contain the additives. The feed of the organic acid group (A) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs. The feed of the phytogenic additive group (F) contained 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. The feed of organic acids plus phytogenic additives group (A+F) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. Compared to groups pigs from the group (F) had by 9.7%, group (A+F) - by 8.3 % and from group (A) had by 3.2% higher mass. The bests results of feed conversion were found in the group (A+F) - 2.84 kg, which was by 8.5% less than in the group (C), whereas the group (F) had by 5.1% and group (A) - by 6.7% better results than the control group. The results of Duodenum and Rectum microflora analyses showed that use of organic acid and phytogenic additives reduced mould yeast Staphylococcus sp. colony formed units (CFU gE-1).

Neosporosis is an infection disease caused by a single celled parasite Neospora caninum that produces cysts in the host organism. The dogs are a definitive host of parasite; cows and other ruminants are intermediate hosts. It causes neuromuscular disorders in dogs and abortions, birth of weak calves and neonatal mortality in cattle. Disease occurs worldwide (Sweden, Germany, Spain, Australia, Canada, USA et al.). Our aim of this study was to clear up how many seropositive animals in two seropositive dairy herds (after bulk milk investigation) in Latvia there are, their relationship and possible changes of their biochemical data. The studies in 2006 between September and November were carried out. In two farms there were 14 seropositive animals (from 67). There was evidence of inheritance of neosporosis infection. No differences were recognized in cows' blood biochemical data between positive and negative animals.

In presented study we have investigated an occurrence of 15 polycyclic aromatic hydrocarbons (PAH) in different smoked meat and fish samples. After clean up and extraction procedures, the samples were analyzed by gas chromatography-mass spectrometry (GC-MS). Large variability in PAH levels for samples of the same type was found, thus the contamination level is not strongly correlated with the type of product. In the smoked fish samples concentrations of total PAHs ranged from 0.26 to 104 mu g kgE1, and in smoked meat samples - from 1.7 to 197 mu g kgE-1. In general, the predominating PAHs in all samples were benz(a)anthracene, crysene, and cyclopenta(c,d)pyrene. Also the elimination of PAHs in smoked fish by UV irradiation was investigated. Significant decrease in carcinogenic PAH content in smoked fish was found after a 15 min exposure.

The dynamic of rapeseed oil oxidizing processes under the influence of light in brown glass, colourless glass, and colourless PET bottles during storage at 18+-2 deg C were investigated. The changes in A and E vitamins content in rapeseed oil packed in colourless PET packaging materials were determined after 4 months storage at 18+-2 deg C at daylight. The connection between different packaging materials' transparency and oxidizing of oil were observed.

The presented study aimed to explore the relationships between different indices of ambient ozone (O3) and tree defoliation, radial increment, and specific diversity and abundance of soil micro-arthropods, stream macro-invertebrates, small mammals (mainly rodents) in order to test the hypothesis that changes in the considered objects of forest ecosystem could be related to changes in ambient ozone concentration. The observations have been carried out on 3 integrated monitoring stations located in Aukstaitija (LT-01), Dzukija (LT-02) National Parks (NPs) since 1994, and Zemaitija (LT-03) NP since 1995. The obtained data revealed that only peak ozone concentrations (from 125 to 215 mug mE-3) had significant effect on changes in the considered components of forest biota. Radial increment and crown defoliation of Scots pine, a little lower the diversity of soil microarthropods, and the least diversity of small mammals were found to be the most sensitive to ozone exposure.

Main factors raised interest about biomass as the source of energy increase renewable resource demand in the context of Green house gases emissions decrease and the problem of environmentally friendly and efficient waste utilization. Legislation of waste water sewage sludge use is becoming stricter now. After cutting away top peat layer of peat quarry, the owners have two alternatives: the first, to flood the fields and transform them into bogs, the second, to carry out some economic activities - one of which must be field afforestation with traditional or fast growing tree species. Before planting trees it is necessary to fertilize the fields, and waste water sewage sludge will be one of potential fertilizers. Aims of research were to determine the impact of waste water sewage sludge fertilization 10 t haE-1 on tree growth and soil properties. Concentration changes of N, P, K, and Ca, Mg in different depth and concentration of S and total C and heavy metal in soil top layer during the year 2006 were determined. The effect of fertilization on tree growth and stock was determined by the non-destructive method, data were calculated by height and root core diameter of trees. Fertilization stimulates tree growth as weed growth too. On peat areas observed soil acidity decreasing. Despite of sufficient amount of nutrients willows were not suitable for peat fields. To avoid increasing of heavy metals content in soils, only qualitative waste water sewage sludge or waste water sewage sludge composts is acceptable for fertilization.

Wood construction elements are widely used in buildings and they can be used in construction elements such as roofs, floorings, windows and doors. As wood is combustible material, there are lot of fire regulations that should be fulfilled at the design stage of any building project. In Latvia, as in some other countries usage of wood in building constructions is limited. Wood materials are an ecologically friendly material and a renewable resource, and its usage should be promoted. The paper presents an overview of heat distribution in wood floorings exposed to standard heat fluxes which is different compared to wood members exposed to high heat radiation. Fire spread and self-ignition investigation on wood floorings is carried out in this research. The results show different kinds of the temperature distribution in the cross section of the wood member cross section depending on heat radiation and location of the temperature measurement point. Temperature distributions in wood during fire can be completely different in dependence on heat radiation and cross section of the wood member. The wood materials in floorings do not reach the self-ignition temperature during standard heat radiation.