part Section I. Basic Approaches -- chapter 1 Modeling Phosphorus Movement from Agriculture to Surface Waters -- chapter 2 Modeling Runoff and Erosion in Phosphorus Models -- chapter 3 Modeling Phosphorus in Runoff: Basic Approaches -- chapter 4 Basic Approaches to Modeling Phosphorus Leaching -- chapter 5 Phosphorus Transport in Streams: Processes and Modeling Considerations -- chapter 6 Uncertainty Estimation in Phosphorus Models -- part Section II. Models -- chapter 7 Phosphorus Modeling in Soil and Water Assessment Tool (SWAT) Model -- chapter 8 Modeling Phosphorus with Hydrologic Simulation Program-Fortran -- chapter 9 Phosphorus Modeling in the Annualized Agricultural Nonpoint Source Pollution (AnnAGNPS) Model -- chapter 10 ANSWERS-2000: A Nonpoint Source Pollution Model for Water, Sediment, and Phosphorus Losses -- chapter 11 Watershed Ecosystem Nutrient Dynamics- Phosphorus (WEND-P Models) -- chapter 12 Modeling Phosphorus with the Generalized Watershed Loading Functions (GWLF) Model -- part Section III. Phosphorus Indices, Best Management Practices, and Calibration Data -- chapter 13 Phosphorus Indices -- chapter 14 Challenges to Using and Implementing Phosphorus Indices in Nutrient Management Planning: an MMP Perspective -- chapter 15 Quantifying the Effects of Phosphorus Control Best Management Practices -- chapter 16 Small Watershed Data Collection to Support Phosphorus Modeling -- part Section IV. Modeling in the Future -- chapter 17 Suggestions to Improve Modeling of Phosphorus.