Voluntary conservation farming practices are measurably decreasing nutrient pollution in the Mississippi River Basin, and this good news: from the Midwest, all the way down the Mississippi River in the Gulf of Mexico. The Indiana conservation trend is reducing the pollution that creates harmful algae blooms and the gulf’s dead zone.
Indiana Wetlands Create Enough Nutrients To Share
In Posey County, by the Wabash River, Brad Smith is leading me through a cypress forest.
“You can see the cypress coming in now,” Smith says, pointing ahead. “These types of cypress stands are almost entirely gone now.”
But the Twin Swamps Nature Preserve can boast a lot of them: tall, grey trunks, rising out of the wetland, with feathery leaves. Parts of their root base, called “knees,” poke out of the water.
Smith is the guy who finds farmers in this area, the Wabash’s floodplain, who want to transition parts of their farms back to wetland. It’s part of the Wetland Reserve Enhancement Program.
A lot of farmers want to participate, because the federal government will pay them. Smith says he doesn’t have to do much convincing.
“I’m not sure how much we sway people to do something that would be counter to their immediate interest of making a living,” he says.
So you have to pay them not to farm it. Smith works for The Nature Conservancy which, along with the U.S. Department of Agriculture, funds the program. Only certain parts of a farmer’s land in eligible for the program. It has to be land that was converted from wetland to agriculture and it has to have wetland soils.
“Typically, where we see these programs being effective are on more marginal farm land, where they might be getting flooded out three out of every five years," Smith says.
Once it’s not being farmed at all, the land converts back to wetland. Smith says this habitat is critical for reducing the amount of nutrients, like nitrogen and phosphorous in water. Crops and vegetables need these nutrients to grow and stay healthy, but they become an environmental hazard when they wash into streams.
It’s a process called “nutrient runoff.” But wetland plants—like cypress trees—love these nutrients; they soak them right up.
“The water get’s cleaned, when it’s out on those floodplains,” Smith says.
How Nutrients From Indiana Make Their Way To The Gulf Of Mexico
Nutrient runoff isn’t a huge problem in Indiana, because the nutrients don’t stay here; they move away with the water. When they settle, like in Lake Erie for example, that’s when they become a problem. Algae love to eat them too, and algae blooms can be toxic to plants, fish and humans.
One of the biggest places this is a problem is way down the Mississippi River, in the Gulf of Mexico, where these algae decompose and form a dead zone—a swath of water almost the size of New Hampshire without any oxygen. Slower fish and plants die and faster animals, like dolphins, swim away.
Indiana contributes about 11 percent of all the nutrient runoff that causes this dead zone, which is a significant amount.
But with this move toward more conservation practices on Indiana farms, more nitrogen has been absorbed in more floodplains and less of it is flowing south. Lee Norfleet, a scientist with the U.S. Department of Agriculture, says that all of the voluntary conservation practices in place between 2003-2006 led to a 34 percent reduction in the amount of nitrogen that ran off of farms and into the Mississippi River Basin.
Norfleet says these reductions are having a positive impact on hypoxia, or low oxygen, in the Gulf of Mexico.
“Reducing those losses has been found to be paramount to addressing the hypoxia issues, which are causing significant fisheries and water quality issues in the gulf.”
The Environmental Protection Agency estimates that by reducing nitrogen losses by about half more—to around 50 percent—we’d be close to preventing the dead zone in the gulf.
Norfleet says the next step is helping farmers better determine which parts of their land are most productive and which parts might be good candidates for programs like the one Brad Smith runs in southwestern Indiana. Norfleet says doing that could significantly lessen the environmental impacts of producing food.