EN
Agricultural activity results in water pollution from nitrogen and phosphorus compounds. Increased concentrations of nitrogen compounds pose a threat to animal and human health. The purpose of this study was to determine the impact of agriculture in a catchment basin on the level of surface water pollution from biogenic compounds. Spatial analysis of the land cover was conducted using GIS and was based on data from the Corine Land Cover databases. The study results indicated that high concentrations of nitrogen and phosphorus compounds existed in the surface waters. In the surface water, high concentrations of biogenic compounds occurred in both primarily agricultural catchments and in urbanized drainage areas. Water may be regarded as eutrophicated or at high risk of eutrophication because the majority of the nitrate concentrations at the monitoring sites exceeded a limit of 10 mg·dm⁻³ NO₃²⁻. Inadequate farming practices and poor sanitary conditions on farmsteads result in the leaching of biogenic substances into the water. To protect water from biogenic pollutants, it is necessary to adopt a new approach to fertilizer use and to improve the sanitary conditions of agricultural properties, which can be achieved by, among other things, the installation of drainage systems in rural areas. Our recommendations include the protection of river valleys as follows: by stopping deforestation, by preserving natural riparian vegetation, and by reducing the volume of intensified agricultural activity or introducing so-called “precision farming.”