Pathways Influencing Catchment‐Scale Phosphorus Export

Despite its many benefits to agricultural production, artificial subsurface drainage represents a major pathway for phosphorus losses from agricultural watersheds. In watersheds with a complex mixture of small fields and landscape parcels, the water quality benefits of best management practices focused on mitigating these losses are most likely to be observed at the catchment scale. However, the site-specific nature of phosphorus fate and transport in drained areas exemplifies the need for additional data to guide implementation of conservation practices at the catchment scale.