To investigate flood and hydraulic parameters of the river, the hydraulic models of the river Daugava near Jekabpils have been built at the Rural Engineering Faculty of the Latvia University of Agriculture and at the Research Scientific Institute of Water Managmenet and Land. Several possible solutions have bee proposed as a results of these investigations, though only the most effective and economically acceptable variant should be selected.

Production of cereals is mostly processed by operating the machinery. Operation of machinery influences the yield, i.e. also the income on one side, but it is also one of the biggest sources of expenses from the other side. Increasing the yearly operation time and amount of work of the machinery leads to decreasing costs per unit. Increasing the yearly amount of work is limited by agrotechnical terms. The crop yield depends on the time and duration of field work, and affects the farm income. The methods and formulae to prognosticate the averageoptimum yearly operation time of farm's machinery, i.e. also farm's cereal-growing area was composed by the author, concerning biological, technical and economical factors and relations, affecting cereal production. Farm profit and profitability were used as optimization criteria.

The field experiment of IOSDV (set up in Tartu in 1989) with application of mineral nitrogen fertilizer in combination with different forms of organic fertilizer (manure, straw) during 2 years has led to changes in mineral nitrogen level depending on fertilization regime used. Crop rotation was the following: potato-spring-wheat-spring-barley. The weather conditions during the period of the study were rather different and it appeared that weather conditions are more important factors in determining mineral nitrogen content and crop yields than applying fertilizers.

The aim of the present research was to determine the level of cholesterol in the milk of the Latvian cow herds and to find out the effect of the milk fat content on the cholesterol level. Milk samples were obtained from the cows of Latvian Brown and Black and White breeds during the morning and afternoon milking. The milk fat and protein were analysed by Milkscan 133, cholesterol content was determined by spectrophotometer CF 26 LOMO. The average milk fat content was 4,45% and average cholesterol content - 20,94 mg 100 ml*[-1). It was found that the cholesterol content in milk was consistently higher to cows the milk of which had a higher fat content and the cholesterol content was different in the morning and afternoon milking.

The aim of research was to analyse the spread of goats eimeriosis in Latvia, determine the structure of eimeria species as well as the efficiency of treatment of goats eimeriosis. Coprological examination of goats, carried out with Fileborn method, showed that the average level of eimeriosis influence on goats was about 25.2% and 3 dominant species of emeria such as E.arloingi, E.ninakohlyakimovae and E.alijevi. The highest level of influence was discovered to animals under 1 year of age, as with E.ninakohlyakimovae (62.5%) as the dominant specie, to animal above 1 year of age - E.arloingi (57.3%-66.7%), respectively. As the result, such preparations as sulfadimetoxine in dosage 75 mg kg*[-1) amprolsol 50 mg kg*[-1) showed high level (about 91%) of efficiency of emeriosis treatment.

In the progressive world, the role of education is continuously growing. International co-operation is a necessary condition for a successful functioning of a higher education institution. In the education process basic compulsory known-how plays a significant role and includes communication, independent and permanent learning, team work, information technology skills and foreign languages. The author presents a research on the role of basic know-how in the labour market.

The epidemiology of barley yellow dwarf disease is highly complex, involving numerous interactions between the abiotic environment and the crop, virus and vector - components of the disease. Barley yellow dwarf is the most economically damaging virus disease of grass and cereal crops worldwide. The disease identified as BYD has been reported in all countries in Europe causing losses on barley and oats, wheat and maize; losses on grasses are recognized but more difficult to quantify. There are five different strains of viruses causing BYD disease and all of them induce similar symptoms of chlorosis and stunting in graminaceous hosts. This report represents an overview of system components and their interactions in the epidemiology of barley yellow dwarf disease. As the main components considered here are aphids - (the only vectors of these viruses), host plants and viruses causing BYD disease. Some aspects of interactions between these components are also discussed.

Latvia has a long-standing traditions in adult education, but only since Latvia regained its independence in 1991, it has obtained a wide public response. Willingness to learn of farmers is increasing every year. The present report describes the latest tendencies in the further education of farmers and states that they are related to changes in social, economical and political situation of the country.