Prairie Strips-An Effective Solution to Pollution

By Steve Eatough

Everyone wants clean water in Door County. Unfortunately, phosphorus and nitrogen are impairing and impacting many of our beautiful water ways, including streams, rivers, and beaches on the bay of Green Bay and Lake Michigan. Phosphorus and nitrate contamination comes from many sources, but much of this pollution comes from agriculture.

Professor Val Klump, former Dean of the School of Freshwater Science at The University of Wisconsin Milwaukee, who’s been studying the bay for decades, estimates that 50% of the phosphorus in the bay comes from agriculture. Milk producers, including CAFO owners, are spreading tens of millions of gallons of liquefied manure on Door County land annually as fertilizer and as a way to dispose of unwanted manure. Cow manure contains high levels of both phosphorus and nitrogen. Our thin Door County soils cannot effectively filter all this manure, so sadly much of it ends up in both our surface and ground water. Rain washes these contaminants into our streams, rivers, and into our lakes. Animal and human waste cause E. coli and blue/green algae blooms in the bay that can make the waters unusable for recreation. Milk producers and their powerful lobbying groups do not, however, appear eager to change any current manure management practices. But what if there was an effective solution that didn’t necessitate changing current manure management practices?

Prairie strips, 15-to-30-foot strips of land on the perimeter of fields, or in-field contour buffer strips, have proven to be a very effective way to manage unwanted contaminated runoff. Prairie strips are like “speed bumps” within and around corn and soybean fields that slow and absorb stormwater. They help keep soil in place and prevent runoff of fertilizers and agricultural chemicals. Prairie strips provide benefits to a greater degree than other vegetation types because of the diversity of the plant species incorporated, their deep multilayered root systems, and their stiff stems that hold up in a driving rain.

Iowa State University has done much valuable research on prairie strips and found them to be incredibly effective. By planting 10% of a field with prairie strip grasses and wildflowers, researchers have found benefits that include a whopping 90% reduction in phosphorus runoff, an 84% reduction in nitrate-nitrogen runoff, a 95 % reduction in soil loss, and a 44% reduction in water runoff. Researchers have also found the prairie strips increase the number of beneficial insects, pollinators and wildlife.

So, what is the downside?  We’re talking about potentially taking land out of production. As farmers know, not every acre of land produces the same yield. Low-yielding acres are a great opportunity to integrate perennial vegetation, reducing the cost of inputs otherwise spent on low-yielding acres. A similar idea applies to conservation, some areas of a field or landscape yield higher conservation benefits than others. By targeting those areas that have high conservation value and low economic return, farmers and landowners can gain disproportionate environmental benefits while reducing the cost of inputs. In addition, the United States Department of Agriculture may still have a plan called CP43 that can provide an owner with annual payments, cost sharing and incentives that offset most of the prairie strips establishment costs. If this program is still being funded, it provides for 10 to 15 years of annual rental payments. Prairie strips are so effective that, perhaps, all of us that benefit can figure out a way to compensate farmers for the land dedicated to prairie strips? What is clean surface water worth in Door County?