Miscanthus Makes Profit On Marginal Acreage

From his favorite front-porch chair, Richard Claybough can literally watch his retirement grow. Just across a small draw, a 40-acre stand of Miscanthus giganteus rises nearly 15 feet into the air on the next ridge. It’s an unusual sight here in southwest Missouri’s Lawrence County, an area dominated by cattle pastures and poultry barns.

Processed fiber from M-Fiber.

“I had that field in wheat, but I just couldn’t make wheat make any money,” Claybough says. “There’s more money in the Miscanthus.”

Claybough is one of dozens of landowners contracted to grow Miscanthus for Renew Biomass, a company based in nearby Aurora, Missouri. The sterile bunchgrass is harvested for its fiber, which is processed and then sold to pet food companies as the product M-Fiber.

“People really care about what they feed their pets, and we want to be the fiber source that they choose,” says Eric Allphin, director of agriculture and quality assurance at Renew Biomass. “We’re a vertically integrated company that grows an all-natural, non-grain, non-GMO fiber product.”

Finding Fiber

Eric Allphin (left) with company president Dustin Dover.

When formulating pet foods, companies seek out sources for fiber, both soluble and insoluble, to improve digestion. While soluble fiber sources, such as grains, are more readily available, Allphin says choices for insoluble fiber are more limited. Often, these sources are byproducts, such as beet pulp or tomato pomace, or a chemically produced product, such as powdered cellulose, made from tree pulp.

“There’s about 20 to 25% insoluble fiber in beet pulp, and tomato pomace is about 40%. Powdered cellulose is about 90 to 95%,” he explains. “With M-Fiber, we have about 85 to 90% dietary fiber and of that, about 80 to 85% is insoluble. So, we’re more like a powdered cellulose in fiber content, but our cost is more like beet pulp and tomato pomace. If you’re buying on pounds of fiber per dollar, we’re going to be the most economical.”

Since 2015, Renew Biomass has contracted with farmers to grow Miscanthus on roughly 4,500 acres in central and southwest Missouri. The company assumes the expense of establishing, harvesting and transporting the grass, while farmers are asked to keep field borders mowed and fertilize the crop once a year.

Rising From Rhizomes

Unlike many other grasses that reproduce by seed, Miscanthus grows from a rhizome, an underground stem much like a root. While rhizomes allow some plants to spread where they’re not wanted, Miscanthus stays within about 3 feet of its parent plant. To propagate, cuttings are harvested from parent plants and then replanted, Allphin explains.

Miscanthus giganteus can grow up to 15 feet in height.

“In December and January while the crop is dormant, we’ll dig rhizomes. We’ll till the ground and then use modified potato lifters to lift those rhizomes out of the ground,” he says. “We’ll sack them up and place them in cold storage.”

In the spring, the Miscanthus rhizomes, which are about the size of a man’s index finger, can be transferred into a new field. Allphin says they prepare furrows on 30-inch spacing in which the rhizomes will be planted.

“We meter them into the ground at a rate of anywhere from 6,000 to 10,000 rhizomes per acre,” he says. “It’s very labor intensive and very expensive to do because there’s not a lot of mechanized equipment.”

In its first year, a Miscanthus planting is fairly sparse as the grass begins to establish. The field won’t be harvested, only mowed to keep weeds down. In the second year, the field will receive fertilization. Renew Biomass recommends that farmers apply about 60 pounds of nitrogen per acre, along with 20 to 40 pounds of phosphorus and 160 pounds of potash.

“The main root system will go down 12 feet, so if you’re planting Miscanthus where you’d planted corn and soybeans for the last 50 years, it’ll mine a lot of the P and K that’s a lot deeper,” he says. “So, a lot of times, we won’t see a big response to P and K [that’s recently been applied at the surface].”

Rapid growth shades out weeds, making herbicide treatments unnecessary. Producers can expect about a 50% harvest in the second year compared to a fully mature Miscanthus stand. Yield increases to 80% in the third year, and by the fourth year, when the stand typically reaches maturity, a producer can expect to harvest 7 to 10 tons of biomass per acre. The typical lifespan for a Miscanthus stand is 20 to 30 years, though Allphin says with good management, the grass could be maintained in perpetuity.

Each fall, the grass goes dormant. Once the grasses’ leaves fall from the standing cane and the cane dries, harvest takes place, usually in January and February. The cane is baled and transported to storage facilities where it remains until processing. The entire bale will eventually be milled into a flour or pelletized before being delivered to a pet food company.

Marginal Ground Mainstay

As a perennial grass, Miscanthus can be grown in USDA Plant Hardiness Zones 4 through 9, from southern Minnesota to central Florida. Its large root system provides erosion control, making it well suited for marginal farmland in the Midwest, Allphin says. It can tolerate both drought and flooding, and he says, “it really likes the heat of Missouri.

“Most farmers have a piece of ground that they lose money on every year, but they keep planting it to corn or soybeans,” Allphin continues. “But if they plant Miscanthus, they now have a stable revenue stream on that marginal ground. They’re not playing the commodity game anymore.”

Hear Eric Allphin describe why Miscanthus is an answer for marginal ground:

Farmers are paid by the ton, and on average, the grass annually nets about $250 profit per acre, although the proximity of a processor, such as Renew Biomass, can affect that price. “That’s a good return for not having a whole lot of labor involved,” Allphin adds.

Back on Richard Claybough’s farm, the producer says he’s satisfied with his current retirement “portfolio.” In addition to the total of 70 acres he has planted in Miscanthus, he maintains some hay acreage.

“There’s another 10 or 15 acres over by the barn where I could plant some Miscanthus, but I’ve got to have something to do. I’ve got to put my hay up,” he jokes. “I’ve done things that I’ve regretted, but this ain’t one of them.”