Refinement of Critically Needed Assessment Tools for Tile Drainage Phosphorus Loading in the Lake Champlain Basin

The goal of this project was to develop a robust APEX model capable of representing edge-of-field P loads (both via surface transport and tile drainage) and to use this model to investigate the impacts of innovative manure management technologies on P loads. This work addresses the need for quantification of P loads from tile drain flow under various conditions, as well as provides a basis for comparing P load from tile flow and surface runoff, and for evaluating factors influencing P movement in tile drainage. It also provides a quantitative assessment of the potential value of manure management technologies in reducing P loads from agricultural fields. Innovative manure management may play a role in improving water quality outcomes at the farm and basin-scale.