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Fig. 2. Schematic diagram of important P pathways and targeted mitigation options taking place along the border of agricultural fields and riparian areas. (A) Downstream part of the river continuum where under natural conditions the river often inundates the floodplain. (B) Middle part of the river continuum where tile drainage pipes often penetrate the riparian areas with water and substances from upland agricultural fields, thus short-cutting the biogeochemical processes in riparian areas. Cutting tile drains and inundating riparian areas can help re-start these retention processes. (C) Most upstream in the river continuum agricultural fields bordering the streams are often steep, resulting in both soil erosion and surface runoff and tillage erosion transport soil and P toward low-lying areas or across the stream edge so that over time low-lying soils bordering streams are enriched in P content.
