EN
This paper discusses research into the seasonal variability of concentrations of total carbon (TC), dissolved organic substances (DOC), and humic substances (HS) migrating with ground water from cultivated fields. Moreover, the effects of biogeochemical barriers such as meadow belts, shelterbelts and small field ponds on limiting migration of the chemical compounds in the agricultural landscape were analysed. It was found that ground water of the studied area contains high concentrations of all examined elements averaging from 44.7 to 73.1 mg/1 of TC, from 224 to 43.6 mg/1 of DOC, and from 6.84 to 20.3 mg/1 HS. It was shown that a 20 m wide meadow belt reduces concentration of TC in ground water by 29%, that of DOC by 44%, and HS by 52%. Moreover, it was found that surface waters of the studied area also contain high concentrations of TC (mean from 65.7 to 78.3 mg/1), DOC (47.8 mg/1), and HS (from 21.3 to 34.0 mg/1). The study results show that such biogeochemical barriers as meadow belts and small field ponds effectively limit the spread of organic compounds migrating with ground water through agricultural landscapes.