Application of manure nitrogen generated by grazing cattle to grazing land within the Pacific drainages of the United States (2012)
The U.S. Geological Survey (USGS) is developing SPARROW models (SPAtially  
Related Regressions On Watershed Attributes) to assess the transport of contaminants (e.g., nutrients) through the Pacific drainages of the United States (the Columbia River basin; the coastal drainages of Washington, Oregon, and California; …