ABSTRACT:
Nutrient management has become a major focus for watershed-scale planning to sustain or improve groundwater quality in certain areas. The USDA Natural Resources Conservation Service (NRCS) Watershed Science Institute (WSSI), in cooperation with a number of partners, is developing a process for creating unique, watershed-scale models to examine dynamic phosphorus (P) flows into, out of and within watersheds using a mass balance approach. The Watershed Ecosystem Nutrient Dynamics (WEND) model tracks watershed P balances over time within each of the several land-use sectors. Long-term impacts of various strategic policy decisions on P cycling both within and export from watersheds can be modeled. The Winooski River Watershed in Vermont is a case watershed in which WEND has been used to evaluate the impacts of long-term strategies on nutrient use efficiency. The objective of this study was to describe the effects of three scenarios (status quo, increased rate of development, and increased conservation policies) on P cycling. The model showed increased water quality impairment over 80 years under the status quo and development scenarios. Under the conservation scenario, P movement into the drainage network was significantly reduced. This suggests that the WEND model could be adopted as an NRCS tool for improved watershed-scale P management.
Footnotes
S. G. Aschmann is an agroecologist and D. P. Anderson is an agricultural engineer for the USDA-NRCS Watershed Science Institute, Lincoln, Neb.; R.J. Croft is a retired water quality specialist at the USDA-NRCS Watershed Science Institute, Burlington, Vt.; and E.A. Cassell is professor at the School of Natural Resources, University of Vermont, Burlington, Vt.
- Copyright 1999 by the Soil and Water Conservation Society
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.