Edge-of-Field Technologies for Phosphorus Retention from Agricultural Drainage Discharge

Abstract

Agriculture is often responsible for the eutrophication of surface waters due to the loss of phosphorus—a normally limiting nutrient in freshwater ecosystems. Tile-drained agricultural catchments tend to increase this problem by accelerating the transport of phosphorus through subsurface drains both in dissolved (reactive and organic phosphorus) and particulate (particle-bound phosphorus) forms. The reduction of excess phosphorus loads from agricultural catchments prior to reaching downstream surface waters is therefore necessary. Edge-of-field technologies have been investigated, developed and implemented in areas with excess phosphorus losses to receive and treat the drainage discharge, when measures at the farm-scale are not able to sufficiently reduce the loads. The implementation of these technologies shall base on the phosphorus dynamics of specific catchments (e.g., phosphorus load and dominant phosphorus form) in order to ensure that local retention goals are met. Widely accepted technologies include constructed wetlands, restored wetlands, vegetated buffer strips and filter materials. These have demonstrated a large variability in the retention of phosphorus, and results from the literature can help targeting specific catchment conditions with suitable technologies. This review provides a comprehensive analysis of the currently used edge-of-field technologies for phosphorus retention in tile-drained catchments, with great focus on performance, application and limitations.

Influence of Floodplain Forest Structure on Overbank Sediment and Phosphorus Deposition in an Agriculturally Dominated Watershed in Iowa, USA

“…Many potential solutions to the issue of accelerated sediment and nutrient loads have been explored, including the use of in-field practices like no-till agriculture and edge-of-field practices like riparian buffers [8]. Downstream mitigation in the form of floodplain deposition also holds potential, as during flood events, floodplain features such as vegetation and coarse downed wood slow water velocities and allow for the deposition of sediment and attached nutrients [9].…”

Effect of water sampling strategies on the uncertainty of phosphorus load estimation in subsurface drainage discharge

“…Edge‐of‐field monitoring of conservation practices is the first step to develop strategies that reduce P load from subsurface drainage discharge. However, edge‐of‐field monitoring requires efficient water sampling strategies to accurately calculate P load (Daniels et al., 2018; Dantas Mendes, 2020; Harmel et al., 2018).…”

Testing a novel sonar‐based approach for measuring water depth and monitoring sediment storage in beaver ponds

“…Measurement and monitoring of sediment storage in small ponds are becoming more important, however, as such ponds are used in numerous nature‐based solution schemes to either attenuate surface water flow, such as in Natural Flood Management and Sustainable Drainage Systems, or trap nutrient laden silt, such as in farm wetlands (Dantas Mendes, 2020; Kovacic, David, Gentry, Starks, & Cooke, 2000; Mander, Tournebize, Tonderski, Verhoeven, & Mitsch, 2017; Nan, Lavrnic, & Toscano, 2020; Posthumus, Deeks, Rickson, & Quinton, 2015; Thorslund et al, 2017).…”