Biomass Upstarts
Four crops that could earn farmers additional revenue.
By Becky Mills
Switchgrass
What’s not to love about switchgrass? The perennial develops a strong root system that holds highly erodible land in place. Plus, if you’ve already planted switchgrass, you know about its long-lasting stands—at least 10 years—and that it makes great wildlife habitat. Now there is better news: more biofuel markets in the future.
Markets: At press time, switchgrass was selling in the range of $60 to $80 a ton, depending on whether it is bought out of the field or delivered to the plant.
Growing region: East of the Rockies, from Florida north to Canada’s 55 N latitude.
Before planting: For fields with decent fertility, you can probably skip the fertilizer the first year, especially nitrogen.
Planting: “It is small-seeded like alfalfa and easy to plant,” says Dennis Pennington, bioenergy educator for the Michigan State University Extension Service. It can be planted in a prepared seedbed or no-tilled, and works especially well in soybean stubble. In his area of the country, planting is from mid-April to late May.
Weed control: “We use a pound of atrazine per acre or quinclorac preemerge,” says Pennington. “Use a scouting program and apply 2,4-D for broadleaf weeds if necessary.” After year two, the bunch-forming grass, which grows 3 to 10 feet tall, shades out weeds.
Establishment: Approximately three years.
Harvest: “The first year, harvest it one time in the fall after it has matured. The forage quality is poor, but the important factor is tonnage.” Adds Pennington, “Wait until it starts to [mature], then it will remove less nutrients.”
Yield: In northern U.S., yield ranges from 4 to 9 tons an acre.
Baling moisture: Below 15%
Storage: Bales
For more information see:
Switchgrass for Biofuel Production
www.extension.org/pages/26635/
Corn Stover
Using corn stover for biofuel seems like the perfect plan. Ample supplies of stover, or the stalks, leaves, husks and tassels left after corn harvest, are a given. For 2013, corn acres in the U.S. are estimated at 97 million and Canadian acres are at 3.6 million, with 2.5 million of those in Ontario. There isn’t much of a learning curve either. If you can grow corn, you automatically know how to grow stover.
Markets: Several cellulosic ethanol plants are located in the U.S. and, at last check, were buying corn stover for up to $70 a ton. As of yet, no production-scale plants are located in Canada.
How much to harvest: “As a general rule of thumb,” says Pennington, “most soils in Michigan need about one-third of the corn stover returned to the soil each year to maintain soil organic matter. This leaves about two-thirds of the crop that could be harvested for livestock feed or biofuels.” In other regions, as much as 50% can be safely removed.
Additional benefits: Says Ian McDonald, applied research coordinator with the Ontario Ministry of Agriculture and Ministry of Rural Affairs, “Removing some of the residue would bring in additional revenue and improve the productivity from no-till planting of the next crop, because of better seed placement and uniformity of emergence.”
Baling moisture: 8 to 12%
Storage: Bales
For more information, see “The Case for Stover.” While there, also watch a video with Iowa State University’s Dr. Matt Darr as he discusses the benefits of harvesting residue.
Other resources:
Corn Stover for Biofuel Production
www.extension.org/pages/26618/
Corn Stover: What is its worth?
msue.anr.msu.edu/news/corn_stover_what_is_its_worth
Miscanthus
Miscanthus, a perennial, is another up-and-comer for the biomass market. However, says Iowa State University Professor Emily Heaton, “I spend a lot of time managing grower expectations about the crop. If you want to plant a half acre or an acre to play with, that’s fine. But let’s [watch what happens] with the corn stover market first.”
Markets: Few large-scale production facilities were receiving Miscanthus at press time, but additional biofuel plants—some that are taking corn stover—may soon offer contracts for Miscanthus.
Growing region: “It is closely related to sugar cane, but more cold-tolerant, so it is better suited for the Midwest,” says Heaton. “It is fairly broadly adapted and can grow from Canada to Mexico.”
Planting: Rhizomes are planted 6 inches deep in the soil, 30 inches apart and in 30-inch rows.
Weed control: Because of the space between emerging plants, weed control is a must for the first year, possibly two.
Establishment: It doesn’t produce mature yields until the third year, but it makes up for that slow start with longevity. Heaton says stands can last 30 years.
Harvest: Harvesting the giant cane-like plant is a challenge, primarily due to ash contamination, says Heaton. However, according to Glenn Farris, AGCO biomass marketing manager, “We have successfully harvested and baled several hundred tons of Miscanthus using our self-propelled windrower outfitted with our RazorBar™ header and biomass auger option. We then baled the material with our Hesston® by Massey Ferguson 2170XD baler. We made very dense bales with ash content under 10%. With the correct equipment and an experienced crew, this material is not a difficult harvest.”
Yield: “We can get 10 tons an acre on fairly poor soils in Iowa,” says Heaton.
Baling moisture: 12 to 15%
Storage: Bales and pellets
Watch the video of Iowa State’s Emily Heaton detailing the potential of Miscanthus.
For more information see: Miscanthus for Biofuel Production
www.extension.org/pages/26625/
Sweet Sorghum
Sweet sorghum is tailor made for biofuel production. “It is easier to make ethanol out of it than [with] corn,” says University of Missouri extension agronomist Gene Stevens. “It is already in sugar form. Just add yeast to start the fermentation.” And as an annual, producers do not have to make a long-term commitment.
Markets: Given the right market conditions, there are as many as 10 plants in the U.S. that accept sorghum. None in Canada.
Growing region: Throughout the continental United States and southern Canada.
Before planting: Excessive tillage can result in topsoil erosion and additional weed pressure.
Planting: Sorghums should be sown after daylight exceeds 12 hours. For most areas of North America, this dictates an early April planting date. Agronomists generally advise that high-biomass hybrids be planted on a 20- or 30-inch row spacing to maintain compatibility with most production systems.
Weed control: If weed pressures are expected to be high, one or several preplant burndowns, using a broad-spectrum herbicide, should be considered. A few examples of herbicides labeled for sorghum include Bicep, Basagran and Expert.
Establishment: Sorghum can produce high yields of biomass in as few as 90 to 100 days in many areas.
Harvest: Until recently, a sugar cane harvester has been typically used after cutting to chop the plants into 2-foot-long billets. However, in a recent study published in CIGR Journal, sorghum was harvested using a Massey Ferguson® dual conditioner. Results revealed that the higher pressures and smaller gaps resulted in faster drying of biomass. Says AGCO’s Farris, “At this point [the sorghum] is very suitable for baling. We have also developed as a prototype a new machine that can billet the material at two to three times the speed of a sugar cane harvester, and it uses less fuel. In a production model, it will be much less expensive than a sugar cane harvester.”
Yield: 20 to 50 tons an acre. Plants, however, can easily grow up to 14 feet tall (higher in some cases), so a high-capacity harvester is required.
Baling moisture: 13 to 17%
Storage: Due to high moisture, sorghum is typically stored as billets, but baling is on the increase.
For more information see:
Sweet Sorghum for Biofuel Production
www.extension.org/pages/26634/
Managing High-Biomass Sorghum as a Dedicated Energy Crop
http://www.bladeenergy.com/Bladepdf/Blade_SorghumMgmtGuide2010.pdf
For refineries that currently accept sorghum
http://www.ethanolrfa.org/bio-refinery-locations/
Biomass crops can be used for a variety of products. Here’s a sampling:
Corn Stover: 1) Animal (primarily beef) feed. Treated with lime makes it even better. 2) Pellets burned for power and/or heat; cheaper substitute for oil. 3) Pellets for animal bedding.
Switchgrass and Miscanthus: 1) Fiber can be used for making paper type products like food containers, bottles, and plates. 2) Also pellets for everything described above.
Sweet Sorghum: 1) Primarily forage and silage as animal feed. 2) Can be used in traditional sugar cane ethanol plants as a substitute or to extend the operating year of the sugar mill which traditionally only operates 200 days per year.