Prairie Conservation Strips Show Promise in Protecting Soil and Water
by Joanna Voigt
The rising price of corn, soybeans, and wheat in recent years has led to a production intensification push in the Midwest and elsewhere, contributing to soil erosion, water quality problems, and threats to infrastructure, and accelerating environmental degradation caused by large-scale monoculture agriculture. As farmers rush to convert every available acre of land to annual row crops in an effort to increase yields profits, lands with great value to ecosystem function and health, such as field borders, riparian buffers, and prairie remnants, are plowed under. Short term gains in revenue come at a high price environmentally as loss of these remaining natural areas has significant and far-reaching impacts on water quality, soil health, and biodiversity.
At the local level, large-scale conversion of the landscape to monoculture agriculture significantly decreases plant diversity and wildlife habitat; increases flooding; decreases soil quality and health; and negatively impacts water quality, increasing sediment and nutrients and leading to problems such as silting in of reservoirs and increased frequency of blue-green algae which can be toxic to livestock.
On a broader scale, large-scale monoculture agriculture results in decreased biodiversity and increased greenhouse gas emissions. and Agricultural runoff from Midwestern states has been implicated as a primary contributor to hypoxia in the Gulf of Mexico. Hypoxia, or low oxygen, occurs when elevated levels of nutrients in the water spur excessive aquatic plant growth, depleting the available oxygen in the water and causing a “dead zone” in which the dissolved oxygen concentration is so low that the water can no longer sustain living organisms. The dead zone in the Gulf of Mexico is the second largest hypoxic zone on the planet, and has significant impacts on biodiversity and ecosystem health in the Gulf, as well as impacting livelihoods.
One practice showing potential for offsetting some of the negative impacts of large-scale, monoculture agriculture is being tested in Iowa and is producing exciting results. STRIPS, which stands for “Science-based Trials of Rowcrops Integrated with Prairie Strips,” is an ongoing experiment developed by researchers from Iowa State University, the USDA Agricultural Research Service, the U.S. Fish and Wildlife Service, and the U.S. Forest Service, at the Neal Smith National Wildlife Refuge in Iowa.
Results of the STRIPS project indicate that planting small areas of native prairie strips in strategic locations within agricultural fields can yield significant environmental benefits.STRIPS are created by planting prairie strips, with a diverse mix of native prairie grasses and forbs, in strategic locations within row crop fields in order to catch runoff before it leaves the field. Deep-rooted native prairie plants create a buffer, which slows runoff, minimizes erosion, and sequesters nutrients and chemicals, protecting water quality both locally and downstream.
The STRIPS project has shown that planting as little as 10% of a row-cropped field to native prairie grasses and forbs can reduce sediment transport by 95%, phosphorus loss by 90%, and total nitrogen loss by 85%. Additionally, prairie strips increase plant diversity and support wildlife, bird, pollinator, and beneficial insect populations.
The Iowa STRIPS project has shown that fields with 10% prairie plantings support twice as many bird species at three times the abundance as fields without prairie strips, the same abundance of pollinators as found in nearby native prairie patches, and 1.4 to 2 times the abundance of predatory insects that target corn and soybean pests as found in fields without prairie plantings.
Native prairie plants increase organic matter in the soil and improve infiltration, boosting soil health and helping to mitigate extreme precipitation events and changing climate conditions. Prairie strips can be managed to support grazing and can be hayed, although the per acre quantity of dried plant material is not exceptional. The cost to implement prairie strips is relatively low, at an average cost of $24 to $35 per acre, and the NRCS CRP program can reduce the cost to farmers by up to 80%, making prairie strips a cost-effective conservation measure.
For more information about STRIPS, visit the STRIPS website at www.prairiestrips.org, and plan to attend KRC’s Farm & Food Conference in Manhattan on November 7 – 8, 2014.
STRIPS researcher, Matt O’Neal, Iowa State University, Department of Entomology, will be delivering a presentation on the STRIPS project on Saturday, November 8. For more information and to register for the conference, please visit http://kansas ruralcenter.org/ calendar/conference-2014/.
Joanna Voigt can be contacted at firstname.lastname@example.org.
From September-October 2014 Rural Papers