Grass production may become a new agricultural wave in southeastern South Dakota if a five-year research project yields positive results.
Since 2008, South Dakota State University (SDSU) researchers have been growing, harvesting and grazing native grasses on 650 acres near Colman. The land is leased by EcoSun Prairie Farms, a non-profit corporation established to demonstrate the economic and ecological benefits of converting cropland to grass production on some of the area’s most productive soils.
“Grass production is an option for a different way of farming,” says Carter Johnson, an SDSU ecologist. “You don’t have as much gross income, but inputs costs are much lower.”
Because South Dakota’s native grasses have been around for thousands of years, Johnson says it was logical to plant them in the former corn and soybean fields.
“They’ve seen about every kind of climatic situation and they’re still here,” he says. “Big bluestem dominates our high-quality forage areas. The mix also contains little bluestem and switchgrass. Big bluestem seems to be most palatable. We’ve harvested it early, about at boot stage, producing both large square and round bales. It has tested between 8% and 10% protein. Most of it has been used to feed cattle.”
EcoSun also produces lower-quality hay, primarily switchgrass, mowing and baling the crop after harvesting the seed. It has generally been used by cattle feeders in feed mixes.
“Harvesting to the ground, we get about 7 dry tons per acre,” Johnson says. “Sometimes we’ve left between 6” and 8” of stubble as fuel for spring burns to control weeds and to stimulate production. With big bluestem, we see nice regrowth after cutting. We leave that in the field as nutrient for next year’s crop. We haven’t fertilized any fields and still see abundant growth.”
Between seed and hay sales, EcoSun has realized between $800 and $1,000/acre gross income from some fields. At the project’s start, researchers expected switchgrass to be in demand for ethanol production.
“I believe that will happen soon,” says Johnson. “Biomass for ethanol is important to the economic feasibility of grass production. If it was a dedicated crop used only for biofuels, that might stabilize switchgrass market prices. Otherwise, switchgrass markets would be as volatile as other commodities and it would be difficult for farmers to rely solely on switchgrass income.”
EcoSun planted a superior prairie cordgrass variety on wetland areas, marketing the sought-after seed as Prairie Farm cordgrass seed.
“If we plant wetlands in fall, they’re usually dry and we get through them with a grass drill,” he says. “If we have to plant them when they’re wet, we hand plant with plugs. That’s a lot of labor, but it can be done. In spring, once water draws down and the mud-flat stage appears, the grass really pops out of the ground.”
The majority of grasses were established with a grass drill. Weeds were a major issue the first year, but few were present by year three.
“Mowing grasses the first year or two after planting helps control weeds. Now we’re down to spot control,” says Johnson. “Getting seed in the ground ahead of warm weather and spring rain is key. If it’s too wet to get it in early, the seed still comes up, but early is best.”
The non-profit sold its first grass-fed beef this past fall. “We’ve used rotational grazing practices, grazing half and leaving half,” Johnson reports. “The cattle don’t stay in any one place very long.”
The researchers will analyze their data after the 2012 growing season to determine the project’s economic feasibility. “Our lease may be extended for more years so we can learn more about making a living from restored grassland,” he says. 