Prairie Strips in Field Crops

There’s a new farming technique on the Midwestern prairie. It’s innovative, it’s sustainable, but it’s also readily available to farmers of all stripes.

This tool is the prairie strip, a strip of native prairie plants grown right in the middle of a grain field.

Benefits

The idea behind prairie strips is to create a buffer zone between the field and the land downhill, holding soil and nutrients in place. A prairie strip blocks soil from flowing away with the rain and thus preventing erosion. It also traps pollutants before they can contaminate a stream.

Preliminary research suggests that prairie strips can accomplish these goals and more:

Reducing soil erosion by about 90%.
Reducing water runoff by about 40%.
Reducing nitrogen loss through runoff by about 85%.
Reducing phosphorus loss through runoff by about 90%.
Improving water quality downstream from the field.
Providing habitat for beneficial insects that pollinate crops and defend them from pests.

How Prairie Strips are Planted

Prairie strips are planted on the contour of the land. Some cut across the field, while others create buffer zones at the edges.

However, prairie strips are different from standard contour buffer strips in that they are planted with strategy in mind. The width of the strip is not fixed, but varies with the runoff situation of each individual field. Also, prairie strips use native plants that are tough enough to stand up to the job of battling erosion, thanks to their sturdy stems and their ability to survive both drought and flooding.

A prairie strip does not have to take up most of the field to be effective. Converting about 10% of the farmed acreage to strategically placed prairie strips is sufficient to reap the benefits listed above.

It takes about three years to establish a prairie strip. Mowing is required the first year to keep weeds in check. Afterward, mowing can be used to kill invasive weeds. Herbicide is also an option after the first year, although it must be applied with precision to avoid harming the desired prairie plants. An established prairie strip can be baled for hay after dormancy, or it can be managed through controlled burning. Grazing prairie strips is a practice that is still being researched, but may be feasible if overgrazing can be prevented.

Prairie strips should be combined with other soil-conserving farming techniques to avoid a rapid sediment buildup at the edge of the strip. Establishment will progress more smoothly where no-till farming is practiced, as tillage damages young root structures.

Making the Transition

Planting prairie strips is not a widespread practice yet, since it is still in the research stage. The number of farmers using this new technique is small, but growing rapidly.

The project began under the auspices of Iowa State University in 2004, and continues to grow with the university’s guidance. By 2013, one farmer was ready to experiment with prairie strips. Last year, over 30 farmers were involved, primarily in Iowa, but also in Missouri.

Of course, prairie strips cost money to establish and maintain. The estimated cost is about $24 to $35 per acre.

Also, prairie strips do take about 10% of the farmed land out of production, reducing total yield. Fortunately, ideal strategic locations for prairie strips typically coincide with the toughest places for corn and soybean plants to grow. Some farmers claim that they have increased their total profits by taking these fragile areas out of production.

It’s rare to see both environmental groups and commodity organizations supporting a common cause, but the new technique has united the Iowa Environmental Council with the Iowa Corn Growers Association, for instance. Despite the drawbacks, prairie strips are promising enough to have both farmers and researchers excited.