Dr hab. inż. Krzysztof Pulikowski prof. nadzw.

Prof. dr hab. inż. Franciszek Czyżyk

Dr inż. Katarzyna Pawęska

Dr inż. Maria Strzelczyk

Participation of nitrate nitrogen in total nitrogen content in waters outflowing from catchment with agricultural use

In paper analyzed the results of research concerning nitrate and total ni-trogen content in drainage effluents as well as surface water coming from facilities located in Lower Silesia area. Detailed analysis were made for participation of nitrate nitrogen in total nitrogen amount. Drainage effluents were characterized by significant content of total nitrogen: average concentration in research period amounted from 22,4 mg N  dm3 to 36,9 mg N  dm3. In drainage effluents, derived from different drainage section, relation N-NO3:N didn't show significant differences and was in the range 75-88%, despite the fact that this water differed significantly of total and nitrate nitrogen content. The increase of average concen-tration of total nitrogen in surface water for both research objects was cause by outflowing drainage effluents that were reached in nitrogen compounds. In drain-age water in summer period showed smaller relation N-NO3:N, what should be explain by intensive absorbing this ion by plants in vegetation period. Regardless of the analyzed period, there was found higher proportion of nitrate in water below research object. Only in case of lowland object these differences were significant for significant level p=0,05. The more fluctuation of relation N-NO3 conducive smaller participation of nitrate nitrogen in total ...

Dr inż. Katarzyna Pawęska

Prof. dr hab. inż. Franciszek Czyżyk

Dr inż. Maria Strzelczyk

Seasonal changes in the size of nitrogen load outflowed from micro-catchments used for agricultural purposes

The paper presents the results of the survey of the daily load of total nitrogen outflowed with drainage system and ditches in Lower Silesia. The volume of daily load shows large seasonal variation. The maximum daily loads were found in object located in the submontane area. These loads amounted for the drainage systems 6,27 kg N  d-1  ha-1 and for the ditches were noted until 12,2 kg N  d-1 ha-1. Significantly lower values were found in the lowland object. In lowland area, risk of polluting the receiver with total nitrogen effluents from agricultural areas, occurs mainly during early spring. At the object located in the submontane area, which is characterized by greater rainfall, there is a second critical period attributable to the July and August. Load of nitrogen outflowed from submontane catchment during the year was 75,5 kg N  ha-1, while from lowland's catchment outflowed much less nitrogen - 12,7 kg N  ha-1. Con-ducted research and analysis clearly show, that the size of nitrogen load outflowed from catchment is determined, to a large extent, the course of weather conditions, particularly amount of rainfall. ...