My dad, raised on a farm and once a farmer, said he could tell what dairy cows ate by the taste of their milk. In his day, cows grazed on perennial grasses and forbs, such as alfalfa and clover. By the 1950s, farmers were using commercial chemical fertilizers to grow row crops. As they plowed more cropland, they turned to corn and wheat—seeds of annual grasses—to fatten, or finish, livestock. But now there's a movement afoot to return animals to pasture.
A growing number of restaurants and food markets feature meat and milk from grass-fed animals. Some customers say they simply prefer the taste of these foods. Market demand also reflects other consumer concerns, including animal welfare and human health.
Conservation is another good reason to restore grazers to grasslands. This issue's lead story, "Where Cattle Roam and Wild Grasses Grow," tells how grazing can help create better wildlife habitat on wildlife management areas.
In partnership with livestock producers, the DNR and other conservation organizations are trying a new twist on traditional grazing. The practice calls for grazing of cattle in a carefully timed and measured rotation, simulating the way bison grazed the landscape over time. On well-managed grasslands, some native plants, such as prairie smoke and pasque flowers, have a chance to multiply. Migratory and resident wildlife alike stand to prosper among a greater diversity of plants of various heights.
Our story focuses on conservation grazing as a tool for managing today's grasslands, including restored and highly degraded prairies. This tool might not prove to be as useful for managing our precious few remnants of original prairie. "The unfortunate situation for native prairies in Minnesota today is that we have relatively small fragments within a sea of invasive species," says DNR ecologist Fred Harris, "[It is] a totally different scene from 200-plus years ago. That's why we should be cautious about how we apply grazing to the best remaining prairies, particularly those with wetter soils or that have populations of rare native species."
Conservation grazing on selected lands has the potential for benefits beyond those cited in our story. Most important, perennial grasses keep the soil covered year-round. With their extensive root systems, prairie plants are especially valuable because they hold soil firmly in place. Grasslands thus help prevent erosion and control runoff and flooding.
At a fall 2012 workshop called Restoring the Soil Resource: Insuring for Resiliency and Profit, Midwestern farmers and ranchers spoke about the advantages of integrating livestock and grazing into their operations. Microbiologist Kristine Nichols discussed her research on soil health. Continuous green cover acts like insulation, she said, keeping soil warm enough for microorganisms to stay active longer. Underground microbial activity not only supports plant life, but it also relies on plants above ground. Management practices such as perennial cover, plant diversity, and grazing systems can improve the habitat for soil livestock. And there can be a lot of livestock, Nichols pointed out: A handful of healthy soil holds billions of organisms—more than all the people who ever lived on Earth.
Earth, the planet, could be the biggest beneficiary of prairie and grasslands conservation. Over a span of 12 years, U.S. Department of Agriculture researchers examined the impact of different cattle grazing scenarios on soil. According to results published on their website, "land that was grazed produced more grass than ungrazed land [did], and grazing led to the most carbon and nitrogen being sequestered in soil." Like trees in the forests, perennial grasses can lock up these major contributors to the greenhouse gas emissions that are warming the world's climate.
To capture all the benefits and address all the threats to our prairie and grassland landscapes, grazing needs to be practiced with conservation in mind. Conservation of natural resources is the ultimate goal and the best guide for measuring success.
Kathleen Weflen, editor