Skip to main content
ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Research Project #439593

Research Project: Contribution of Legacy P to Watershed Outcomes - Phase 1

Location: Soil Management and Sugarbeet Research

Project Number: 3012-12210-001-011-I
Project Type: Interagency Reimbursable Agreement

Start Date: Jul 31, 2021
End Date: Jul 30, 2026

The general objective of this two-phase project is to discern the potential contribution of legacy P sources to watershed P discharges/dynamics through USDA-funded research in the Snake River (Kimberly, ID), Upper Mississippi (St Paul, MN), Lower Mississippi (Oxford, MS), Lake Erie (West Lafayette, IN and Columbus, OH), Chesapeake Bay (University Park, PA and Beltsville, MD) and Lake Champlain (Burlington, VT) watersheds. The focus will be on smaller watersheds where USDA-ARS or its partners have conducted, or are carrying out, research related to legacy P.

The project will take a two phased approach, informed always by modeling but building off of empirical work that we initiate in phase 1, which will support well-documented watershed modeling in phase 2. This agreement covers work for Phase 1. Phase 1 – Characterize legacy P sources in research watersheds, with locally derived, and common, methods. This will involve sampling soils and sediments, hopefully around areas where there are experiments and monitoring (esp. nested). Some samples will be analyzed at a common lab per methods TBD. We will also use existing models (SWAT, APEX, AnAgNPS, SPARROW, others) to inform our decisions on metrics so that they may be implemented later. The emphasis will be on P characterization, but sediment budgeting/sourcing should be encouraged. Phase 1 – Assess long-term (>5 yr) Edge-of-Field and small watershed data to assess contributions of new/recent/incidental vs. old/legacy/chronic sources. Legacy P partners and others (CEAP watershed) will contribute data. Data will be analyzed per routines lifted from WRTDS or by other methods. Phase 1 – Advance management recommendations to comprehensively address legacy P and non-legacy P sources, including to be used as scenarios by watershed modelers.