CZYNNIKI KSZTAŁTUJĄCE WŁAŚCIWOŚCI SORPCYJNE POWIERZCHNIOWEJ WARSTWY GLEB WYKSZTAŁCONYCH NA ZBOCZACH DOLINY NARWI W OBRĘBIE OTULINY NARWIAŃSKIEGO PARKU NARODOWEGO

The aim of the study was to describe the sorption properties of the surface layer of soils formed in different parts of the slope. The study was carried out within the protection zone of the Narew National Park on 12 individual arable fields, located on the slopes of the val ley of the Narew River. The surface layers of the studied soils are loamy sands and sandy loams. The pH H2O in these soils ranges from 4.83 to 7.85, and pH KCl ranges from 4.03 to 7.81. Sorption capacity of the surface layer of the studied soils is quite small, ranging from 4.19 to 20.10 cmol(+) kg -1 . On gentle slopes composed of material weakly susceptible to erosion a major factor in moving soil material on the slope are agricultural practices, resulting in slight differences in physico-chemical properties and texture of the surface