STRIPS Tips and Resources
Expert advice for planting prairie strips.
By Linda Askey
Determining Your Seed Mix
Seeds prices vary, depending on what a farmer wants to put into the mix. Tim Smith, who farms 800 acres of corn and beans in Iowa, speaks from recent experience, “You can spend a couple hundred dollars an acre or a thousand dollars an acre. Whatever you want.”
For success, about 4-6 species of grass are recommended—both cool and warm season grasses—and then the balance can be forbs. With the news about declining monarch butterfly populations, most prairie strips contain milkweed, as well. A nurse crop of an annual species like oats should be included to hold the soil while the slower prairie species get established.
When to Plant
The good news is that seeding strips can be done when the farmer gets to it. Says Tim Youngquist, a farmer liaison for the STRIPS program, “To me, fall is the ideal time to do it. A lot of the forbs’ seeds, the flowers, they are going to have pretty tough seed coats that will need cold stratification, just being out in the freeze/thaw cycle to break open and germinate. So fall plantings can generally develop about a year faster than a spring planting.”
For additional information on planting prairies strips, see http://www.leopold.iastate.edu/sites/default/files/pubs-and-papers/2014-11-landowners-guide-prairie-conservation-strips.pdf
Mowing Is a Must
“From a maintenance perspective,” says Youngquist, “you would want to keep it mowed in that first season. Really, it depends on how often you can get out there and mow.
“Our recommendation is to convert about 10% of a field. That’s going to be a time commitment to get that mowed. So, we tell people not to let it get higher than about 16 inches. You can keep it even 10-12 inches.
“The big thing you want to avoid is that if it gets away from you and gets to be 2-3 feet tall, and you cut it, it windrows all that material down onto your seedlings. That’s going to be a negative. I can’t minimize the importance of that maintenance mowing. That can really be the difference between a successful planting and a failure.”
Prairie Plant Benefits
Prairie plants, as compared to traditional cover crops, are deep rooted. For instance, big blue stem grass has roots that penetrate the soil 10-12 feet deep; brome can be 1 to 1 1/2 feet deep.
Although prairie strips do not aspire to the diversity of virgin prairie that can have 200-300 species, the diversity of 10 to 30 or so species in a prairie strip seed mix means that, although not all species will be adapted to field conditions, some will be. (Over time, those planting prairie strips can experiment with which species work best for their land.) And with deep root penetration, there is greater moisture penetration and reduced runoff.
Measures of Success
Disproportionate benefits of strategically placing prairie strips in 10% of a field results in more than a 10% improvement in loss of soil, phosphorus and nitrogen—a lot more. STRIPS have been shown to reduce soil sediment runoff by 95%, phosphorus by 90% and total nitrogen by 84% when runoff was compared to that from a field of no-till row crops with no remediation.
Research shows a 380% increase in desirable native plant species in a STRIPS watershed compared to those without. That means the seed mix is only the beginning; nature will improve the mix over time.
Studies are ongoing or planned to document potential:
- Increased water percolation on-site and decreased impact to flood-prone areas
- Increased habitat and food sources for wildlife
- Increased nectar and pollen sources, as well as host plants, for monarchs and pollinator insects
- Enhanced beneficial microbial activity in the soil
Response to the success of prairie strips has stretched the STRIPS team pretty thin these days, working to answer the next set of research questions, as well as getting technical service providers trained to help satisfy requests for assistance designing and planting prairie strips. Interest is coming from beyond Iowa, as well. Conservation issues are similar for farmers throughout the prairie states and into Canada, and it seems many are interested in STRIPS.
The STRIPS team expects to host several field days at demonstrations sites this year. For more information about the STRIPS program and field days, visit prairiestrips.org. A demonstration plot at the Neal Smith National Wildlife Refuge—see http://www.fws.gov/refuge/neal_smith/—is open to the public.
Small Changes, Big Impact: Prairie Conservation Strips: http://www.leopold.iastate.edu/sites/default/files/pubs-and-papers/2014-07-small-changes-big-impacts-prairie-conservation-strips.pdf
STRIPS Research Overview: http://www.nrem.iastate.edu/research/STRIPs/content/research-overview
STRIPS Videos: http://www.leopold.iastate.edu/news/strips-video
Basic Information about Nitrate in Drinking Water: http://water.epa.gov/drink/contaminants/basicinformation/nitrate.cfm
Milkweed In the Mix
Word is getting out about the importance of milkweed plants to avoid the extinction of the migratory monarch butterfly (see Monarchs and Milkweed). The toxicity of milkweed to grazing animals has long been a concern. However, prairie strips have not proven to be nutritious forage, nor is it recommended; grazing in prairie strips also is not recommended. In addition, research has shown that animals will avoid the bitter milkweed if sufficient forage is provided.