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Perennials Have Potential In Low-Productive Land

If crops were a baseball position, miscanthus would be the right fielder of the crop world. Right field is where youth baseball coaches have placed earnest but initially untalented players. At worst, it’s the position where they can do the least amount of damage. At best, it’s a place where late bloomers can unfurl their talents.

Perennial grasses like Miscanthus x giganteus are like that. On prime cropland, corn and soybeans still beat this perennial hands down. On marginal ground, miscanthus can really shine. At current prices, this is the ground where you may be losing money on row crops. Economics can then join traditional environmental benefits of nitrate-leaching reduction up to 90% and slice slope erosion by 80% to 90%, says Emily Heaton, Iowa State University associate professor in biomass crop production.

Perennial Perks
Perennials provide alternative options for biofuels, feedstocks, energy, and livestock bedding. Of all perennial grasses, the most productive is miscanthus.

Miscanthus is gaining in popularity for biomass production. The warm-season perennial originates from Japan. This particular hybrid, different from ornamental varieties, is sterile and requires vegetative propagation via rhizome planting or by planting plugs.

“There are few inputs for perennials,” says Tim Mies, director of energy farm operations with the University of Illinois department of crop science. “You do have to switch your mind regarding cash flow when going from annual crops to perennials.”

Eric Rund farms ground near Pesotum, Illinois, with a stream meandering through it and a filter strip on either side.

“Although I was farming outside the filter strip, it wasn’t the best ground,” says Rund. “That’s where I started.”

Rund’s decision to plant miscanthus was based on the fact that it was his poor ground on which soils had degraded through erosion. That soil loss gave him the push he needed to try miscanthus.

Planting occurs in the spring with harvest in the late winter. There’s an up-front cost for planting miscanthus that farmers aren’t use to, says Tom Voigt, Extension biomass specialist at the University of Illinois.

Production costs vary according to miscanthus development stages. The cost of rhizomes for planting usually ranges between $700 and $1,200 per acre, says Heaton. However, establishment costs are balanced over a 20-year crop that has an annual harvest. Hiring custom planting will save on machinery costs.

Target planting populations for miscanthus are 7,000 plants per acre on 30-inch spacing.
Miscanthus establishment is the main cost, says Rund. He has been growing miscanthus for eight years and is an advocate for it. A different mind-set is required for miscanthus production vs. traditional row-crop production.

“You don’t plant in the spring and harvest in the fall. It’s not like a forestry project where you wait 20 years for a return on investment, either,” Rund says.

“There’s a trade-off between cost of establishment and the long-term higher yields,” says Mies. Weed management is essential during the year of establishment. A preemergent and postemergent herbicide should be applied. Several herbicides are labeled for miscanthus, such as Harness, says Voigt. Avoid grass herbicides, since miscanthus is a grass.

“Miscanthus will reach 6 feet tall by the first of June,” says Voigt. “Weeds in the field are not that common. The plants grow rapidly, though, so weeds can’t compete.”

For fertility, Heaton recommends 50 pounds of nitrogen per acre in the second year. Maintenance fertilizer applications in subsequent years have low costs and can boost stands. 

Miscanthus can be harvested with conventional hay or silage equipment in the second year of production, explains Heaton.

“By the third and fourth year, you start seeing the full potential yield,” says Mies. “There’s a lag that row-crop farmers aren’t used to dealing with. It takes several years to see a return on that.”

After the first year of planting, harvest can occur from December through the end of March, says Voigt.

“The quality is better in March than December, but the yields go down,” he says.

Rund considers it as a third crop, and he currently sells it for livestock bedding. “Harvest is done using a silage chopper,” he says. “What comes out is a product very similar to wood chips, but two to three times more absorbent than wood chips.”

At $85 a ton for bedding, Rund can match the net income from an acre of miscanthus to that of an acre of corn yielding 200 bushels per acre at a price of $5 per bushel. Rund believes the larger market is still for energy. However, that market has yet to fully develop.

“There is a lot of work being done with cellulosic ethanol, and eventually the conversion processes may become practical and offer good markets for many kinds of biomass,” says Rund. “Near term, a more likely use for biomass is to burn it to produce thermal energy for small- to medium-size applications. Besides the simplicity of this approach, you can extract about 85% of the energy in biomass through combustion vs. 35% converting it to liquid fuels first.”

“Heating with biomass can be half the cost of heating with LP gas,” explains Rund. “An acre of miscanthus can provide the equivalent heat of 1,360 gallons of propane, and the equipment to burn it is proven, available, and very scalable.”

The biggest challenge for farmers will be identifying markets. The real key is finding the markets in close proximity to where you are growing it, says Mies.

“The market has to be considered before you plant any crop,” he says. “If you don’t have a consistent identified market, you end up fighting for where to sell your material. Hopefully, as the industry develops, there will be multiyear contracts available to incentivize investments in feedstocks.”

Rund stopped pushing so hard for the adoption of miscanthus because of the lack of a market.
Miscanthus could produce 60% more ethanol than grain corn, says Voigt. “Inputs would be less, as well,” he says. “With corn, you’re replanting, and the inputs are greater than they are with miscanthus.”

They’re just waiting for demand. “We have an infrastructure that works for corn and soybeans,” says Voigt. He believes there will be an adoption once there’s a developed market.

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