Abstract
Controlling phosphorus (P) inputs to lakes remains a priority of lake management. This study develops watershed P balances for 11 recreational lakes in Minnesota. Areal P input rates to the watersheds ranged from 0.32 to 6.0 kg P ha-1 year-1 and was linearly related to the percentage of watershed in agriculture. Watershed P retention ranged from 10% to 89% of input P. Although many best management practices work to increase P retention (by trapping P in basins; reducing erosion; filtration), P retention is not sustainable indefinitely, particularly in "hot spots" such as septic leach fields and heavily manured fields. The watershed P balance tool is a framework that can allow watershed managers to develop novel strategies for managing P. P management strategies should be developed to keep P inputs and exports in balance so that P does not accumulate; long-term P accumulation is not sustainable and can eventually lead to lake eutrophication.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 294-304 |
| Number of pages | 11 |
| Journal | Ecological Engineering |
| Volume | 29 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2007 |
Bibliographical note
Funding Information:This study was supported by the U.S. Forest Service, with additional support from NSF Biocomplexity Project EAR-0322065. We thank Stephanie Snyder, the USFS project manager, for her support throughout this project and her thoughtful review of this paper and Sue Leitz (USFS) for GIS support. We also thank the many state agency staff and people in the case study counties who provided insights regarding these lakes and their watersheds (see Schussler, 2005 ).
Keywords
- Lake management
- Phosphorus
- Phosphorus accumulation
- Phosphorus retention
- Watershed
