Studies at Mississippi State University are finding that when it comes to providing forage for livestock, native grasses may be best.
Sam Riffell, an associate professor of wildlife ecology and management in the Department of Wildlife, Fisheries and Aquaculture, is examining the benefits of replacing exotic grasses, commonly used in Mississippi grazing pastures, with native, warm-season grasses.
"The ecological advantages of native, warm-season grasses over bermudagrass are evident," Riffle said. "Native grasses are more drought-tolerant, require less fertilizer, and remove carbon in their root systems."
But the economic advantages are not immediate, as these grasses require a period of establishment and systematic management for the greatest yield return.
"It takes one to two years to establish native, warm-season grasses, so that's an increase in opportunity costs," Riffell said. "But the long-term savings may lie in the few inputs."
Riffell and graduate student Adrian Monroe received a graduate student grant from the Southern Sustainable Agriculture Research and Education to develop sample budgets for establishing or converting to warm-season grasses.
They are also examining the benefits of native grasses for wildlife. Monroe said native grasses provide better habitats for breeding birds than does bermudagrass.
"Bermudagrass tends to restrict the movement and foraging of breeding birds," Monroe said. "Native grass pastures may mimic prairies, with bunch grasses providing nesting structure and spaces for movement."
Native grasses, such as switchgrass, Indiangrass, little blue stem and big blue stem, were abundant in Mississippi before the days of its first European settlers. Their growing season in Mississippi is from mid-April through late October.
In the 1940s, the U.S. Department of Agriculture introduced exotic grasses into grazing pastures, including bermudagrass from Africa and bahiagrass from South America. These exotic grasses, which are easily established and palatable to livestock, have been widely used ever since.
However, native grasses are making a comeback.
Rocky Lemus, forage agronomist with the Mississippi Agricultural and Forestry Experiment Station and MSU Extension Service, is examining the challenges and benefits of establishing native, warm-season grasses for grazing livestock.
Lemus and his team are conducting a native grass variety trial throughout the state. They are testing common grasses native to Mississippi in five locations.
Lemus said that native grasses are better for the environment than exotic grasses and improve soil quality.
"Bermudagrass requires a lot of fertilizer, which tends to acidify the soil," Lemus said. "On the other hand, native grasses require less fertilizer and drop leafy organic matter back into the soil, actually improving soil nutrient cycling and increasing microbial activity."
Lemus acknowledged the initial expense and time required to establish these grasses. He suggested allowing a year to remove the bermudagrass before planting native grasses.
"If you don't do a good job killing bermudagrass, it's going to create a lot of competition for the native grasses to get established," he said.
"In the first couple of years, rotating livestock and grazing grass at 6 to 8 inches will allow native plants to recover more quickly and maintain productivity and quality," he said. "Rotating livestock in native grass pastures will also increase the sustainability of these forages, with many lasting 12 to 15 years without significant inputs."
Despite the initial cost and effort, Lemus said the investment will pay off in the long run. Once established, native grasses yield 6-8 tons per acre annually, compared to bermudagrass at 3-4 tons.