EN
Results of three-year water quality monitoring programs carried out in two small, lowland agricultural watersheds of various fertilization level: the Upper Little Vermilion River (ULVR) located in Central Illinois and the Zagoż- dżonka River located in Central Poland, were analysed. Nitrate and orthophosphate concentrations and loads are presented and discussed in relation to meteorological conditions and hydrological responses of the watersheds. The watershed with intensive agricultural practice (ULVR) generates the runoff with higher concentrations of nutrients. Concentrations of the considered nutrients were, in the case of N-N03 about 7.1 times, and in the case of P-P04 about 1.6 times higher in the ULVR than concentrations in the Zagożdżonka River. Nitrate-nitrogen losses amount to a significant part (about 15%) of applied total nitrogen fertilization in the ULVR. High concentration of P-P04 in runoff from Zagożdżonka watershed has also been recorded.