HERD ABOUT IT?
by Ana Grarian
Published: October 20, 2010
NY Times Opinion Page
Every year, usually beginning in late spring, an oxygen-depleted dead zone forms in the Gulf of Mexico at the Mississippi River’s mouth, killing off fish, shrimp and other marine life. By the time cooler weather restores life to the zone, the fishing industry has sustained substantial losses.
Scientists have long known that the dead zone — this year it covered 7,000 square miles — is created largely by nitrate washed downstream from fertilized fields as far north as Minnesota. A study in the Journal of Environmental Quality by scientists from Cornell University and the University of Illinois has now conclusively identified the largest source of that nitrate: tiled farm fields.
For as long as farmers have been farming in the Midwest, they have been laying drainage tile — often perforated plastic tubes installed 2 feet to 4 feet below the surface — to drain wetlands and create arable fields in places that would normally hold standing water. The problem is that the system also sluices away nitrogen fertilizer, which eventually flows through tributaries into the Mississippi and ends in the Gulf of Mexico.
Mark David, a University of Illinois researcher, observed that “farmers are not to blame.” We agree. Tiling is as old as Midwestern farming. What’s needed now is more research and direct incentives from the Agriculture Department to find ways to mitigate this problem.
These include: restoring wetlands, where possible; growing cover crops to absorb water in the spring, when runoff is heaviest; different methods of applying fertilizer; and even methods of treating the runoff before it reaches creeks and rivers. Sacrificing life in the gulf for corn in the fields is a trade-off that has to stop.
This isn’t just a “midwest thing”. Here in CNY miles of field tile are laid to drain wet spots out of fields. We did it. We thought it was good farm practice. After all we were just draining water into the nearby creek right? Turns out we were wrong. Of course even just draining water is not neccesarily a good thing. Wetlands help the slow absorption and transfer of water into streams. This helps to mitigate runoff of soil, and flooding downstream. It also allows for water to transfer into the local water table and aquifers, making it available later on for plant growth and wells. Today with the aggressive use of fertilizers, herbicides and pesticides, field tiles direct a lot more than water downstream.
Another curious turn of events is the practice of building wetlands. Well we don’t want this wet spot here, because we want to build here, so we’ll destroy this wetland and build a man made one over here, several miles away. Sort of like carbon trading with water.
Does anyone really believe that we can do this well? Maybe there was a good reason for the wetland to be there in the first place? Wouldn’t it be easier and, actually better, to build on a secure dry spot? Wasn’t there a song about the wise man and the foolish man and where they built their houses?
Such is the hubris of homo sapien,
and it usually comes back to bite us in our gluteus maximus.