Investigating the influence of a well-drained and a wet buffer zone in relation to nitrogen and phosphorus leaching in the temporary groundwater from an agricultural field to the nearby stream, using Maglemose Å as a case study

Stefanie Sean Robins & Lærke Bloch Noer

Student thesis: Master programme thesis


This study examines two different agricultural fields and the buffer zones that separate those fields from the nearby stream, Maglemose Å. In addition, another locality was chosen in a small wetland area around a small tributary connected to the same stream. The three chosen localities had changing hydrological conditions from relatively dry conditions to relatively wet. The test localities were chosen in order to investigate the temporary groundwater, specifically the flow from the field to the stream and to investigate its nitrate and phosphorus transference through the buffer zone and the possible denitrification. The study investigates if the two buffer zones retained nutrients from entering the stream and the parameters needed for the maximum retention capacity of a soil based on the findings from the temporary groundwater in these two buffer zones and a literature study to back the findings up. The samples were taken in a period from November to April 2017.
The concentration of nutrients in the temporary groundwater was measured by placing observation wells in the soil and into the zone of the temporary groundwater in perpendicular lines from the field and down slope to the stream, and to low lying reeds and analysing the soil water for nutrient concentrations.
The study found that the wet buffer zone had a higher denitrification potential and had less nitrate in the soil water than the dry buffer zone which had an eight times higher concentration of nitrate. From a literature study it was found that the wider a buffer zone is, the better it retains phosphorus.

EducationsEnvironmental Risk, (Bachelor/Graduate Programme) Graduate
Publication date28 Jul 2017
Number of pages98
SupervisorsNiels H. Jensen