It’s a late fall afternoon, and I am walking along a four-year-old prairie strip that was planted by Valley Stewardship Network, where I work. The ground is pretty sloped, but farmable – certainly in this part of the country – angling down through a corn field to the woods, through a valley, and into a stream not far below. The stream is a local example of an outstanding cold-water creek, well known for excellent trout fishing and gorgeous, pastoral views.
On one side of me is the apex of American agriculture – uniform rows of weed-free field corn, over seven feet tall, with rapidly ripening cobs that will be harvested in the next month. On the other side is the prairie strip, a wild array of over 35 plant species, jumbled together, with six-foot tall yellow Indiangrass, big bluestem grass, blooming plants like asters, three varieties of goldenrod, grey headed coneflowers, rosinweed, and all the remnants of a dozen or more summer blooming flowers.
The farmer had installed this prairie strip as a way to reduce erosion gullies that were forming as the water rushed off the fields during rain storms. These prairie strips are like the contour strips we are used to seeing, but they use native prairie plants instead of alfalfa. Back in the 1930s when rain-caused erosion was a terrible problem, the Soil Conservation Service of the Federal government suggested using contour strips of alternating crops (like corn and alfalfa) to slow down the water and reduce erosion, which along with other landowner practices helped reduce erosion significantly.
As dairy farming changes, though, and the alfalfa used by the dairy cows isn’t in as much demand, many of those contours have been removed and just a single crop, such as corn or soybeans, is planted. Fence rows between fields, which also slowed water down and provided habitat for pheasants and other birds, have been removed as larger and larger single-crop fields have become more efficient and profitable.
Then, in 2003, Iowa State University started studying putting native prairie strips into crop fields much like alfalfa contours, and determined they could dramatically reduce water flowing off the land, hold onto nutrients like phosphorus and nitrogen in the field instead of shooting them down into streams, and improve the soil’s ability to hold moisture long after the rain – All big benefits for the farmer! In the field where I’m walking the original erosion gully is completely gone, with no costly ground work for the famer in four years.
The loss of topsoil is an often unseen but very expensive problem for today’s farmer. In our hilly area, an average of 4 tons of soil is lost per acre per year, including the nutrients in that soil which the crop needs to flourish. Prairie strips have been shown to significantly reduce erosion, and can hold phosphorus and nitrogen in the farm field. As a benefit to the trout stream below, that sediment and those nutrients won’t be dumping into the creek, keeping it healthier and helping support the burgeoning tourist trout fishing industry in the area. The idea of using prairie strips in the uplands to help reduce water flowing off the land and hold it in place can be a key practice to helping reduce flooding downstream.
An interesting characteristic of prairie plants is they grow better in poor soil, which is often the case on the edge of crop fields near trees. The trees use much of the nutrients and water along field edges, competing with the crops, and can shade the plants. These field edges are often uneconomical to crop – it actually costs more in plowing, seeding, fertilizing and harvesting than these edges yield in crop value. Enter prairie strips – by not farming these edges the producer can increase profits, reduce erosion, and improve biodiversity – a win, win, win.
The addition of these 35 native plant species dramatically increases biodiversity. It supports a doubling of bird species and pollinator species (things like bees, butterflies, moths, beetles and bats) in and around the fields! In a crop of uniform corn or soybeans, it only takes one pest, one fungus, one drought, or one flood to have great impact. With so much diversity in the strip, there are 35 different species that can react to changes in the environment – some will flourish in any given year, and some won’t. Every year and every season when I see a strip, I am amazed at how different it will look as different species thrive. Perhaps it was a dry winter, or a warm winter, or a wet spring – something out of that broad mix of species will like that combination! Sometimes the strips are dominated by a grass, or a flower, or yellow flowers will flourish, or purple, or tall or short – it’s such a joy to watch them change.
What is striking as I walk between the two fields is how different the two feel, sound and smell. The prairie strip is alive in every respect. Thousands of bees, butterflies, moths, beetles and other insects are flying around and buzzing and pollinating. Birds call and flit in and out of the grasses. The spicy, herby smell of the plants is nearly overpowering. Despite a dry fall, the soil is still moist.
The corn field, by contrast, is silent, with no movement of insects or birds. The soil is dryish, especially compared to the STRIP. This isn’t to knock the field of corn, which supports a farm family and generates income and energy and food, but if you’re an insect or bird or soil microbe, the field of corn is a desert. In fact, the top four crops grown in Vernon County don’t require pollinators at all – corn, soybeans, alfalfa and oats have all been bred over the years to self-pollinate, a much more reliable and repeatable growing habit than hoping bees and butterflies fertilize your crop or not. If every pollinator disappeared tomorrow, we’d still have all four crops (but lots of other problems!).
In Vernon County, we have 507,000 acres of land. About 64,000 acres are planted to corn every year (USDA National Agriculture Statistics Service), 37,000 acres of alfalfa, 32,000 acres of soybeans and 5,000 acres of oats. So, if you’re a pollinator, fully 27% of the landscape is a hostile, barren desert. With the use of pesticides to help protect the crops, that area isn’t even just neutral, it is a deadly place to be. Interspersing these crops with small areas of prairie STRIPS can have a huge impact in supporting these insects and birds.
And it’s not just for farmers. In Wisconsin, the average yard size is ½ an acre – and Vernon County has a bit over 11,000 homes, so about 5,000 acres of grass. Grass is almost as tough for pollinators and birds as a corn field – a monoculture of non-native grasses with fertilizers, pesticides and herbicides added! Solid surfaces like roofs, driveways, sidewalks and streets add significantly to water runoff. To help with that, urban landowners can do the same thing as these farmers, and add native prairie ‘strips’ to their yards. If each homeowner put just 10% of their yard into native prairie and shrubs and trees, we’d add almost 500 acres of bird friendly plants alive with bees and butterflies and beauty and smells to our county! It would also help each municipality reduce the impacts and costs of stormwater runoff, and the streams downstream of the towns would be cleaner and healthier.
The impetus for the prairie strip I’m walking by was reducing erosion, but the reasons are different for every landowner – some want to reduce erosion; others want to improve stream water quality by reducing nutrient runoff; some want to have a prairie with the blooming flowers and grasses; some want to specifically add habitat for birds and pollinators; still others want to add habitat for game birds or deer. The beauty of the strip, though, is no matter the initial reason, all of them are improving water quality and adding habitat and biodiversity to the area.
Valley Stewardship Network was one of the early adopters of this approach in Wisconsin, helping farmers and landowners to plan, seed and care for their strips, and now we’ve put in over 54 acres of strips in Vernon and Crawford counties. We continue to do landowner consultations, to see if prairie strips or other practices can improve the environment and the bottom line. Thanks to every one of those landowners for helping, and for everybody who may plant one in the future, whether on a farm, recreational land, a park, or in town!
You can get more information from website for VSN (https://valleystewardshipnetwork.org), the Iowa State University (https://www.nrem.iastate.edu/research/STRIPS) or the Tallgrass Prairie Center (https://tallgrassprairiecenter.org).