The study aimed to determine the level of contamination by dioxins of the forest soil samples collected from two sites not adjacent to potential sources of industrial pollution. The results were compared with the data on soils from the Warsaw area and from non-contaminated areas (natural background). Chemical analyses showed that the amount of dioxins contained in the forest soils was 0.48 and 4.70 ng ∙ kg^-1, respectively. These values correspond with those characteristic of the natural background (1.0−5.0 ng ∙ kg^-1 soil), suggesting that dioxins have not accumulated in the forest soils and thus do not pose any threat to the living organisms.

Selected landscape indicators (soils, rainfall, slope angle, slope length, and current land-use pattern) were interpreted from the aspect of water and material motion dynamics on a slope in the model area of Dolná Malanta (near the town of Nitra, Slovakia). The interpretation focused on the specification of soil erodibility. On the basis of the expected dynamics of water and material motion and their integration along the slope it was possible to propose five alternative solutions for protecting arable soil against erosion. The proposals aim at conserving the fertility of soil and are based on a thorough evaluation of the natural conditions and the current use of the area.

From May 1995 to December 1997 and from February 2002 to October 2003, seven quality indicators of water in four mid-field ponds situated in the Odra river valley in the area of the Brzeg Dolny dam, differing in the conditions of water supply, were studied on a monthly basis. The investigations included also surveys of the floral composition of the ground cover around the ponds, water surface measurements with depth sounding, observations of water levels in the ponds, and weekly measurements of groundwater levels in the adjacent area. It was found that the physicochemical composition of water in the ponds depends not only on the existing hydro-meteorological, geological and soil conditions or the land use and management pattern of the valley but also on the local processes of oxidation and reduction.

Research conducted in the own catchment of the Warta river between Oborniki (km 206.3) and Skwierzyna (km 92.2) aimed at determining factors contributing to the self-purification of river water. The following factors were considered: land use, soil type, lake density, precipitation and air temperature over a 10-year period, as well as precipitation chemistry, river-bed morphology, and use of riverside zone. As shown by the results, the small proportion of arable lands with the large proportion of forests and lakes in the catchment, as well as the afforested river banks create favourable conditions for reducing the inflow of nutrients to the Warta water. It was also found that air temperature in the summer half-year considerably affects the concentration of Kjeldahl nitrogen, ammonia nitrogen, total phosphorus and phosphates in river water, while precipitation in the winter half-year contributes to the washout of nitrate nitrogen from the catchment.

The spatial distribution of the concentrations of sulphur and nitrogen dioxides as indicator pollutants of air was determined on the basis of studies conducted in July and December 2001 within the Pleśna district. The location of passive samplers corresponded with the basic types of land development. The isolines of SO2 and NO2 concentrations were shown on maps. The trends of changes in the seasonal mean concentrations of suspended dust, SO2 and NO2 in a 5-year period (1995-1999) were established using data obtained from the Provincial Disease Control Centre in Tarnów. The results of the research provided the basis for performing quality classification of the district areas according to air pollution levels (maps were drawn) and for identifying the areas suitable for housing development.

Using the cadastral district of Borský Mikuláš as an example, the paper discusses soil erodibility in the region of Záhorie (western Slovakia). The area of interest belongs to the most affected Slovak regions because its natural and anthropogenic conditions favour the occurrence of wind erosion. The following factors determining the intensity and course of wind erosion are considered: soil properties (texture, compaction), climatic factors (temperature, rainfall), velocity and duration of wind, and anthropogenic factors (ploughed fields, vegetation cover). Equations of soil transport, taking into account the velocity of wind (at a dry soil surface), were developed for four texture classes. It was found that the main factors responsible for wind erosion in the research area are the large proportion (90.1%) of light soils, increased dustiness due to the high velocity and duration of winds, and lower rainfall total than in other regions of Slovakia. Thanks to the cultivated crops that reduce the intensity of wind erosion, not more than 14.9% of arable lands (12.9% of agricultural soils) are threatened by strong erosion. The results of the research may be applied (with minor corrections) to the whole region of Záhorie Lowland.

The studies were designed to examine the influence of varying rates of ash-and-sewage and ash-and-peat blends on the yield of a grass mixture with birdsfoot trefoil and the levels of iron, cobalt, manganese, aluminium and silicon in the mixture. A pot experiment was conducted on mineral soil to which ash-and-sewage and ash-and-peat blends were added at a rate of 1-30% of the total weight of soil. The experimental design included also treatments comprising only individual components of the blends. The yields of plants depended on the treatment and study year, ranging from 9.61 to 135.38 g d.m. · pot-1. The highest yield was obtained in the third year, and the lowest in the first year of experiment. In treatments with ash, peat or their blends the yield was significantly lower than in the control treatment (mineral soil). Ash-and-sewage blends added to the soil significantly increased the yield, whereas ash-and-peat blends had a decreasing effect. The element contents of the grass mixture varied according to the treatment and study year, and were in the following ranges: 49.57-104.99 mg Fe; 0.04-0.58 mg Co; 20.67-713.87 mg Mn; 20.81-42.69 mg Al; 28.78-64.07 mg Si per kg d.m. The silicon content systematically increased, and the levels of iron, cobalt, manganese and aluminium decreased with the increasing proportion of ash-and-sludge and ash-and-peat blends.