title: Accounting for the risks of phosphorus losses through tile drains in a phosphorus index.
abstract: Tile drainage systems have been identified as a significant conduit for phosphorus (P) losses to surface water, but P indices do not currently account for this transport pathway in a meaningful way. Several P indices mention tile drains, but most account for either the reduction in surface runoff or the enhanced transport through tiles rather than both simultaneously. A summary of the current state of how tile drains are accounted for within P indices is provided, and the challenges in predicting the risk of P losses through tile drains that are relative to actual losses are discussed. A framework for a component P Index is described, along with a proposal to incorporate predictions of losses through tile drains as a component within this framework. Options for calibrating and testing this component are discussed.
authors.affiliation: Agriculture and Agri-Food, Canada. keith.reid@agr.gc.ca
authors.forename: D Keith
authors.initials: DK
authors.lastname: Reid
authors.forename: Bonnie
authors.initials: B
authors.lastname: Ball
authors.forename: T Q
authors.initials: TQ
authors.lastname: Zhang
mesh_terms: D000383:Agriculture; D003247:Conservation of Natural Resources; D004784:Environmental Monitoring / Q000379:methods*; D008962:Models, Theoretical; D010758:Phosphorus / Q000737:chemistry*; D012307:Risk Factors; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus