The use of Geotextiles as a Filter for Phosphorus in Overland Flow in Southern Ontario

Session: 39. - Managing Agriculture Water and Nutrients - Science Solutions for Tomorrows BMPs

Ryan Carlow, University of Waterloo, [email protected]
Merrin Macrae, Univ. of Waterloo, [email protected]
Janina Plach , University of Waterloo, [email protected]
Mazda Kompani, University of Waterloo, [email protected]
Richard Brunke, OMAFRA, [email protected]

Abstract

Phosphorus (P) is a key nutrient in agricultural systems but also contributes to eutrophication in waterways. The dominant pathway for P loss in many fields across Ontario is surface overland flow, where P can leave fields in both particulate and dissolved forms. Overland flow may occur during and following heavy rainfall or snowmelt events. To reduce P losses in overland flow, geotextile filters (Filtrexx) were deployed at the edges of two well-managed cropped fields in southern Ontario. Water samples taken before and after the filter material were collected during overland flow events occurring between November 2016 and May 2018. Samples were analyzed for both dissolved and total forms of P, total suspended sediments and anion/cation concentrations. Results show that the filter material has the ability to remove both SRP and TP and reduce TSS loads, but this is not consistent across all runoff events. Temporal variability in the efficacy of the filters with season, flow magnitude and P concentrations will be discussed. The implications of utilizing geotextile filters in combination with more commonly used BMP’s for P reduction will also be presented.  

1. Keyword
phosphorus

2. Keyword
hydrodynamics

3. Keyword
management

4. Additional Keyword
Agriculture

5. Additional Keyword
BMP's