Preventing “dead zones” like the one that has accumulated around the mouth of the Mississippi River in the Gulf of Mexico is easy! Farmers should just stop using fertilizer! We’re kidding, of course. Societies relying on agriculture require fertilizer, and we need to develop solutions that reflect that. Too often, we point the finger at “over-fertilization,” a complaint that isn’t too realistic. A more realistic solution to these problems is intelligent drainage systems.
This might seem counterintuitive; don’t drainage systems, in the end, take runoff toward rivers and other watersheds?
True, but consider a corn farm with no drain tile. Rainwater saturates the land, and any nitrates that haven’t been sapped up by the crops end up draining into the local watershed. OK, so now we’ve got organized streams moving toward the river. How does this make the nitrate problem any better?
What happens next in your drainage system is where the nitrates find their solution. There are several plans that have been developed by farm scientists for dealing with nitrates, and all rely on organized drainage.
One idea that has gained in popularity is the woodchip bioreactor. This is a trench, ranging from 50 to 120 feet in length, and three feet deep, filled with woodchips. These bits of wood provide a source of carbon, which promotes bacteria that, in turn, process the nitrates remaining in the water. This process has been demonstrated to remove up to 45 percent of nitrates from drainage.
There are some rules-of-thumb to consider: Experts from the University of Illinois suggest that the water must spend roughly six hours within the trench for optimal performance. The longer and skinnier, the better!
Imagine it as a water filter attached to your kitchen sink; the drain tile brings the runoff to the filter, where it is treated naturally, and released in a more healthy’ livable form.
Saturated buffers are an even bigger idea that has picked up endorsements from the EPA and other agencies. As the name suggests, these installations serve as a barrier of sorts between your cropland and watersheds, in the form of an artificial wetland.
Drain tile feeds runoff into a water control structure, which helps distribute the drainage along a stretch of buffer land. This soil stores the excess nitrates and nutrients, where they’re taken in by microorganisms (just like in a real wetland).
One benefit to this system is that it removes up to 80 percent of nitrates out of the potential runoff. One even bigger benefit to farmers? These buffers can actually push nutrients back to your crop. An EPA report showed that the installation of saturated buffers actually boosted crop yield by up to 20 percent.
Being environmentally friendly, and profiting from it? That’s a win-win. And it all starts with drain tile.