By Jason Tetrick
Native grassland habitats have steadily dwindled since the settling of Iowa in the mid-19th century and the development of modern agriculture in the mid-20th. Corn and soybean cropping systems now extend across the landscape in place of what once was largely prairie.
Through conservation efforts, prairie remnants have been protected here and there to conserve native ecosystems. These little pieces of ecological history have withstood the test of time and are important for understanding how ecosystems have functioned in the past.
Corn and soybean cropping systems and native habitat are at two ends of the ecological spectrum in terms of diversity and complexity. But what about the places where agriculture and nature thrive together, grow alongside each other and benefit from one another? Could such a place exist?
It does exist. And it exists just a stone’s throw from the Chichaqua Bottoms Greenbelt, a 10,000-acre conservation area. Four miles down the road sits Carney Family Farms.
Farming, nature working together
Surrounded by adjacent corn and soybean fields, Bruce Carney’s cattle have been grazing on perennial forage for the last 22 years. After starting out with 200 acres of row crops and 100 acres of pasture in 1998, Carney has since transitioned his entire 300 acres to pasture. Today, Carney Family Farms produces grass-finished beef, lamb, and pasture-raised pork and poultry.
Carney’s cows move to new paddocks daily, which allow the freshly grazed pasture time to recover, and this is critical for grass productivity and building soil health.
But rotational grazing is just part of Carney’s ecological efforts. Land surrounding his creeks is in the Conservation Reserve Program to help prevent streambank erosion. He’s used the Environmental Quality Incentives Program to help pay for mobile electric fencing and watering systems. And he’s enrolled in the Conservation Stewardship Program, which helps farmers manage their land for productivity and conservation.
Carney stays in contact with Chichaqua Bottoms Greenbelt staff, collaborating with them on grazing projects. “I’ve planted a lot of trees around the farm to add diversity and stack enterprises,” he adds. “I’m trying to figure out how I can make this farm viable for the next generation to come here and make a living from it.”
Noticing more kinds of wildlife
After transitioning his farm out of row crops in 2008 to pasture, Carney has witnessed growth in the populations of wildlife and biodiversity on his farm including deer, turkey and pheasants. He hopes to someday see quail. “I can remember hunting them, and they were a lot of fun,” he says.
A few years ago, Carney started noticing more than just deer and pheasants. He spotted and heard some interesting birds he had never seen in the past. At the time, he didn’t realize it, but the birds he was seeing and hearing were bobolinks, a species known to thrive only in healthy grassland ecosystems.
Carney didn’t know what they were or that they carried any importance, but he started reading about them in conservation publications. “That’s when I realized I must be doing something right,” he says.
Carney is a member of Practical Farmers of Iowa and knew other members were interested in researching the benefits of grazing for bird populations, so he worked with PFI staff on a research project.
Conducting on-farm research
PFI, Polk County Conservation and Drake University teamed up to start an experiment. Keith Summerville, professor of environmental science and sustainability at Drake University, and student researchers Grace Baumgartner and Conner Willis conducted bird counts in 2016. The experiment compared Carney’s grazing systems — both perennial and annual — with the ungrazed, reconstructed prairie at Chichaqua Bottoms Greenbelt.
Baumgartner and Willis conducted bird counts in all three habitat types weekly from May to September in 2016 and 2017. Restored prairie in the conservation area supported the least amount of birds, while both types of Carney’s rotationally grazed pastures supported nearly double the amount of birds in each year.
Carney’s bobolinks, which sparked the research in the first place, were not present in the prairie, but were found in both types of pastures. You can read more about the findings in the research report Monitoring Birds in Rotationally Grazed Pasture.
Results show no difference
The results showed no significant difference between the two pasture types, although the most birds were counted in the perennial pasture. “I think the annual species get so tall that it’s hard for the ground birds to forage in it,” Carney says. “I was surprised that 300 acres with row crop all around it was enough to attract all these birds and still have the same amount of birds as a 10,000-acre conservation area, but it’s obvious it does.”
Summerville says the key is moving cows daily and managing forage so there’s a good amount of biomass remaining for the birds to nest after the cows move to the next paddock. The cows aren’t grazing clear to the ground, which would destroy certain species’ current or potential nesting habitat.
“Cow activity does two things: changes vegetation structure and exposes more ground,” Summerville says. “Some birds like short- and tallgrass mixtures and exposed insects, which attracts insectivorous birds.”
Grazing supports bird habitat
Wild bird populations can thrive in properly managed agricultural landscapes. Carney and Baumgartner observed that certain birds followed the cattle as they grazed. Cowbirds and swallows were the most abundant birds counted in the study and could be found in great quantity in the pastures when cattle were present.
“They eat flies and insects off the cows’ backs,” says Carney, “and when the birds manage the flies and other insect populations, it helps keep the stress level of the animals down.”
Summerville adds, “Multiyear assessments are needed to make grazing recommendations that support bird habitat, but we know grazing later in the season is better for the birds. Farmers must decide what their goals are. If the goal is to manage for nesting birds, any disturbance that clips the forage to the ground will eliminate nesting habitat.”
Grassland diversity makes it work
Both Carney and Summerville agree that these two systems need to complement each other. “We need [conservation areas] too; we need both,” Carney says. “But I think there’s a huge benefit to grazing and the different heights of grass.”
“It’s important to remember that prairies and pastures complement one another to protect a larger population of birds than either habitat alone,” Summerville says. ”Codependent conservation strategies are needed.”
After two years of research with PFI, Carney Family Farms and Drake University have continued conducting this research into 2018, learning more about nesting and which birds prefer the grazing habitats. The 2018 report is still being put together, and the research will continue through 2019. You can learn more about this project and other PFI research projects at practicalfarmers.org/research.
Tetrick writes for Practical Farmers of Iowa