A study was carried out in 2014–2016 at three comparable, representative areas of permanent grassland situated on organic soils within the Pasłęka River valley, in Kiewry (53°53′ N, 20°10′ E, Poland) near Olsztyn. Soil samples were collected during the growing season from selected objects located at a distance of 50 m, 150 m and 300 m from the Pasłęka River bank, which determined their use. Physicochemical properties were determined in the soil samples. The aim of the study was to assess the physicochemical properties of the soil in a selected area of the Dolina Rzeki Pasłęki Natura 2000 site depending on the habitat conditions and land use. The factors that determined the use of organic soils at the site were the prevailing habitat conditions. At a high level of groundwater, which caused high soil moisture, a given site was used as natural meadow. However, at a low level of groundwater, which was associated with low soil moisture, it was intensively used as grassland for hay harvest. Peat and muck soils of moderate moorshification in the uppermost layers, covered with a natural meadow (occasionally mown) and situated 50 m away from the Pasłęka River bank, were characterised by the highest total nitrogen and phosphorus content in all layers compared to the other objects. Correlational relationships between the current moisture content, soil air content and the soil abundance of general forms of macronutrients were determined by the location of a grassland in relation to the distance from the river and the depth of the organic layer within the soil profile. The results of the research obtained at the Natura 2000 Site called Dolina Rzeki Pasłęki’ (the Pasłęka Rivery Valley) show that the land use variants do not affect the degradation of organic soils.  

24.2.2019