Studies were conducted on surface waters of mid-field ponds in agricultural watershed. The resarch were aimed to perform introductory assessment of ammoniacal nitrogen's and nitric nitrogen's aswell as phosphates concentrations in surface waters. The studies have been performed from March to October, 2015 to 2017. The highest concentration of phosphates were detected in year 2017, whereas the highest concentrations of these were experienced in June in every year. The lowest concentration of phosphates were detected in the first year of studies (2015). The average concentration of phosphate got higher every year. Phosphates' concentrations got higher from March to October, however, the decline were experienced in later period. Conducted research confirmed the dependence, that in lower temperatures the concentrations of ammonia cal nitrogen were generally lower than in the months with higher average temperature. The highest average concentration of ammonia cal nitrogen (0,29 mg•kg^-1) was detected in the first year of studies (2015). Average concentrations of nitric nitrogen’s fluctuates from from 0,15 to 0,24 mg•kg^-1. In every year, the concentrations of nitrates were highest in June. The lowest concentrations of nitrates in 2015 and 2016 were experienced in August, and in July of 2017.