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Research article - Peer-reviewed, 2018

Nitrogen and Phosphorus Removal from Agricultural Runoff in Integrated Buffer Zones

Zak, Dominik; Kronvang, Brian; Carstensen, Mette, V; Hoffmann, Carl C.; Kjeldgaard, Ane; Larsen, Soren E.; Audet, Joachim; Egemose, Sara; Jorgensen, Charlotte A.; Feuerbach, Peter; Gertz, Flemming; Jensen, Henning S.


Integrated buffer zones (IBZs) represent a novel form of edge-of-field technology in Northwest Europe. Contrary to the common riparian buffer strips, IBZs collect tile drainage water from agricultural fields by combining a ditch-like pond (POND), where soil particles can settle, and a flow-through filter bed (FILTERBED) planted with Alnus glutinosa (L.), a European alder (black alder). The first experimental IBZ facility was constructed and thoroughly tested in Denmark for its capability to retain various nitrogen (N) and phosphorus (P) species within the first three years after construction. We calculated the water and nutrient budget for the total IBZ and for the two compartments, POND and FILTERBED, separately. Furthermore, a tracer experiment using sodium bromide was conducted in order to trace the water flow and estimate the hydraulic residence time in the FILTERBEDs. The monthly average removal efficiency amounted to 10-67% for total N and 31-69% for total P, with performance being highest during the warm season. Accordingly, we suggest that IBZs may be a valuable modification of dry buffer strips in order to mitigate the adverse impacts of high nutrient loading from agricultural fields on the aquatic environment.

Published in

Environmental Science and Technology
2018, volume: 52, number: 11, pages: 6508-6517

Authors' information

Zak, Dominik
Aarhus University
Aarhus University
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Jensen, Henning
University of Southern Denmark

Sustainable Development Goals

SDG6 Clean water and sanitation

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use

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