In many ways, the Barycz Valley is a unique region. For one thing, it contains the highest number of fish ponds in Poland. Secondly, it is free from heavy industry and large cities. Thus, this region may be considered considerably clean, and the observed concentrations of trace elements are typical for non-degraded environments. There is, however, a threat of excessive accumulation of trace elements such as Zn, Pb and Cu in waters of the rivers in the Barycz drainage basin, received from point sources, and especially supplied with wastewater. These rivers play a very important role; namely, they are the source of water for filling up numerous ponds [Marek 1989]. On the other hand, any seepage of river waters into the groundwater may cause excessive concentrations of trace elements in soils near the ponds. The objective of the study was to analyse and assess sorption properties of sandy soils used as hay meadows. As the study was conducted in a special bird protection area (SBP) included in the European Ecological Network Nature 2000, special attention was paid to the content of selected trace elements. The following analyses were performed on the collected soil samples: particle size distribution, pH in 1 mol KCl ∙ dm-3, TOC, N total, content of exchangeable base cations (Ca+2, Mg+2, K+, Na+) and total content of the metals Fe, Mn, Zn, Pb and Cu. The genesis of the examined soils seems closely linked to the very wet moistened local environment, which significantly influenced the physical and physicochemical soil parameters. These soils were formed in a region crisscrossed by a dense network of watercourses of the Barycz River drainage basin, with strong ominant aquaculture traditions. The sum of base exchange cations (S) and cation exchange capacity (CEC) in the examined soils are strongly affected by the particle size distribution, the fact confirmed by significant positive relationships with the silt fraction and colloidal fraction, and significant negative correlations with the sand fraction. Higher content of Zn, Pb and Cu in surface genetic horizons of the examined soil profiles may point to the anthropogenic origin of the metals. Despite the dominant sandy texture, the soils are characterised by a thick humus horizon, abundant in TOC and TN, which increases their capacity for trace element accumulation. Our assessment of the contamination of these soils with Zn, Pb and Cu did not demonstrate any excess in terms of the permissible levels of the trace elements.

19.1.2014