Save the Bay, Save Your Life, Dr. Neal Barnard, The Huffington Post, May 16, 2011 (He's referring to the Chesapeake Bay here, but mourns what we're doing to the Gulf too.)
I don't know if it's better to let agricultural run-off flow into streams, rivers, and gulfs or to block it so it seeps into groundwater. I can't imagine we'll suddenly stop using so much fertilizer.
The nitrogen-in part, the part where we add nitrogen to soil to help plants grow, was bad enough. How do we manage the run-off? But it was the nitrogen-out part that made be squirm:
"The problem is not just fertilizer, though. Poultry manure--high in nitrogen and phosphorus and produced in enormous quantities (650 million pounds per year in Maryland)--also pollutes rivers and disrupts ecosystems. Innovative chicken farmers have found a way to get rid of some of it: Believe it or not, they feed chicken manure to cattle. As long as cattle feed is no more than about fifteen percent manure, cows do not balk at it."Just a second.
In Maryland, Focus on Poultry Industry Pollution, New York Times, November 2008