Small water bodies located in agricultural areas, so-called in-field ponds, are relicts of the last glaciation. They are characterized by high biodiversity, in addition to which they are astatic and subject to strong anthropopressure due to agricultural production, leading to their eutrophication. The main factors indicating water eutrophication include phosphorus and nitrogen compounds, but of significance are also heavy metals, trace elements and other macro- and microelements contained in water. The study was conducted in two small, in-field ponds in temperate climate. The aim of the undertaken study was to analyse and assess selected macro- and microelements in surface water of two in-field ponds and in groundwater under cultivated soil adjacent to the ponds. The content of the following elements was tested in water: Mg, Ca, Fe, Mn, Na, K, Zn. Among the analyzed macro- and microelements in the studied surface water and groundwater, the highest mean values were observed for calcium and chlorides, and the content of all the elements can be presented in the following order: Ca > Cl > Mg > Na > K > Fe > Mn > Zn. The highest levels of Ca, Cl, Mg and Na were recorded in groundwater under an intensively farmed field in Stare Czarnowo and in the in-field pond located in the middle of this field. Significant seasonal changes in the content of particular macro- and microelements were observed, with frequent peaks, primarily in the summer and autumn, resulting from the mobilization of internal resources from the bottom sediment or water flora.  

24.1.2019