Temporal and Spatial Variation of Nutrient Levels in the Nemunas River (Lithuania and Belarus)

There are discordant results on trends in nutrient river water quality from the economical transition countries in Europe. The present study assessed the impact of these economical changes on the load and concentration at 17 monitoring stations along the Nemunas River and its major tributaries (Lithuania and Belarus). Three time periods were evaluated: the Soviet rule command system period 1986–1991, the transfer to market economy period 1992–1996 and the post reform period 1997–2002. The most surprising result in this study, was the increased area-specific load of NO₃-N from the first to the third period at almost all the sampling sites. The increase was particularly large (43–78%) at the sites in the Lithuanian part of the river. The corresponding load increase in the Belarussian part of the river was only 1–15%. The statistical analyses of concentration data confirm the strong upward NO₃-N trend at the Nemunas mouth and at 5 of the 6 tributaries in the lower part of Nemunas. Temporal and spatial analysis of nitrates transport in the Nemunas River and its main tributaries revealed that nitrates mainly originate from agricultural areas. The upward trends were most likely an effect of ploughing of pastures and unbalanced crop fertilisation in combination with large storage and accumulation of soil-nitrogen during the Soviet period.On contrary to nitrate-N, the area-specific load of PO₄-P decreased significantly from the first to the third period at all sites along the Nemunas River (31–86%). Seasonal (SMK) and Partial (PMK) Mann-Kendall tests on PO₄-P concentrations also showed significant downward trend at 14 of 16 investigated sites. The decrease of PO₄-P levels was attributed to the reduction of municipal and industrial point source emissions and to the decreased livestock numbers.The NH₄-N load showed the same pattern as PO₄-P. At the river mouth the load was 90 kg km⁻² yr⁻¹ during the first period compared to only 20–30 kg km⁻² yr⁻¹ in the third period. The trend test on NH₄-N concentrations detected significant downward trends at 5 out of 16 sites. The declines were explained by decreased emissions from cities and large animal breeding farms.This study showed that trend analysis at multiple sites in a river basin is crucial for the understanding of the variability in time and space. Such analysis is also important for our interpretation of underlying sources and fluxes in a drainage basin over time. This is particularly important for compounds that have different source origin.     

Industrial waste minimization--experience from Lithuania.

Waste represents the loss of both material and energy resources. Because excessive waste generation is a symptom of inefficient production processes, low durability of goods and unsustainable consumption patterns, waste quantities can be considered as an indicator of how efficiently society uses raw materials. Therefore, good waste management begins with preventing waste from being generated. The objective of this paper is to present the work related to waste minimization in Lithuania by introducing successful examples from industry, to bring ideas and inspiration to authorities, companies, and others working in the field of waste minimization. The paper is supporting EU waste policy manifested in the EU waste strategy and the proposed Sixth Environmental Action Programme. Many enterprises are still unaware of the full costs of waste management. Therefore, by applying the methodology presented in the paper, companies could make substantial reductions in their waste, and therefore, disposal costs. Waste minimization (WM) often results in substantial savings through reduced purchasing costs and more efficient practices. It also has wide environmental benefits such as reduced energy consumption and less environmental pollution, conservation of natural resources and extension of valuable landfill capacity. Therefore, waste prevention should have the highest priority in waste strategies, as this is the only way to stop the growth of the amount of waste and reduce the loss of resources (EUC Bulletin 12, 1996).     

Factors affecting N and P losses from small catchments (Lithuania)

Most of the important factors causing differences in nutrient losses and their interaction were analysed in three small catchments that are located in partially different geographic and climatic conditions in Lithuania. The investigation revealed that climatic factors change the amount and pattern of water discharge over year (larger water discharge during winter in the catchment located closer to the sea), but nutrient leaching is more dependent on land use. Agricultural factors, such as larger cultivated area and excessive fertilisation in one catchment cause larger nitrogen losses (15 kg N ha^–1 year^–1). Large area of non-intensively used grassland leads to very small nitrogen losses (5.7 kg N ha^–1 year^–1) in another catchment. However, larger water discharge combined with loamy sandy soils leads to comparatively high nitrogen losses (12 kg N ha^–1 year^–1). The highest P losses (0.318 kg P ha^–1 year^–1) occurred in the catchment with hilly relief and clay soil texture. In summary, extensive agriculture in the post-Soviet countries has reduced the importance of agricultural activity for the extent of nutrient losses and agricultural factors (cultivation, fertilisation and livestock density) are responsible for the losses only in the region of sufficient agricultural activity (N input – 71.5 kg N ha^–1, livestock density – 0.87 LU ha^–1).