Increasing biomass through double-cropping system nets mixed results

December 6, 2010
The research plots included single-cropping sorghum plants (three taller plots in the background). In the foreground are the double-cropping plots where sorghum has recently been harvested and triticale has been planted for the upcoming winter. This photo was taken in early fall. ISU courtesy photo

( -- Trying to increase the amount of biomass available for ethanol production has led Iowa State University researchers to explore a double-cropping system that netted mixed results.

Researchers planted triticale, a relative of wheat, in the fall and harvested it in the spring. Then they planted in early June and harvested it in mid-September.

Twelve different varieties of sorghum were tested with the triticale. Of those, four test plots produced as much biomass as a single crop of sorghum alone yielded in the same year.

"The sorghums planted with the single-cropping system were planted a little earlier and harvested later," said Ben Goff, who received his master's degree from Iowa State University student and is now pursuing his doctoral degree at the University of Kentucky. Goff conducted the research under the guidance of Ken Moore, professor of at ISU.

The longer growing season for the single-cropping sorghum produced more biomass in eight of the 12 sorghum types. The other four types of sorghum were early maturing varieties, and they produced an equal amount of biomass as the single-crop sorghum. These yielded less ethanol than the single-crop sorghum.

While the research didn't produce an increase in biomass, there are benefits to the double-cropping system, according to Goff.

"The winter crop reduces ," said Goff. "And some studies have shown that having the crop in the field captures spring nitrogen early in the year so it doesn't move through the soil profile."

Sorghum and triticale were chosen as the crops to pair together for several reasons, according to Goff.

"Sorghum is a potential ," he said. "You can get a lot of biomass in a shorter growing season. Also, sorghum is more drought tolerant, and using a two-crop system may leave you with moisture limitations. Sorghum has many of the same farm practices as corn, so it would be a crop farmers would be comfortable with producing."

Sorghums, especially sweet sorghums, have high concentration of soluble sugars which are readily fermentable for ethanol, according to Moore.

Triticale is a good winter crop that produces much biomass during the winter, said Goff.

The research was conducted near the ISU campus in Ames and also at ISU's Northwest Research and Demonstration Farms in O'Brien County, and was funded by the Iowa Energy Center.

While the research didn't net an increase in biomass, Goff doesn't declare the idea a failure.

"This still has potential. If we can get an earlier maturing annual winter crop, I think we can get greater yields," said Goff. "Basically, we are trying to utilize more of the sun's energy to produce more biomass."

Moore thinks that sorghum double-cropping may be environmentally beneficial in certain farmland.

"Double-cropping may have some real benefits for land that should not be exposed to erosion in winter," Moore said.

Explore further: Growing sorghum for biofuel

Related Stories

Growing sorghum for biofuel

November 10, 2010

Conversion of sorghum grass to ethanol has increased with the interest in renewable fuel sources. Researchers at Iowa State University examined 12 varieties of sorghum grass grown in single and double cropping systems. The ...

Forage sorghum shows promise as energy crop

March 30, 2010

( -- In their continuing effort to evaluate crops that can serve as biofuel feedstocks as well as cover crops (and that can fit into crop rotations in Pennsylvania and the Northeast) researchers in Penn State's ...

Sorghum feeds Africa, proves important for U.S. as well

February 2, 2010

( -- Sorghum, a main food crop in many African nations and the second most important animal feed crop in the United States, has the potential for expanded food and fuel uses both here and abroad, said a Purdue ...

Self seeding: An innovative management system

April 15, 2008

Winter cover crops provide important ecological functions that include nutrient cycling and soil cover. Although cover crop benefits to agroecosystems are well documented, cover crop use in agronomic farming systems remains ...

Biofuels research searches for new sources

August 3, 2006

The words are becoming familiar, even if the products aren't: biofuel, biobased, biodiesel, bioethanol. All refer to fuel that's made from bio-produced materials such as plants. Chengci Chen (pronounced Chen-see Chen), an ...

Recommended for you

Mammal long thought extinct in Australia resurfaces

December 15, 2017

A crest-tailed mulgara, a small carnivorous marsupial known only from fossilised bone fragments and presumed extinct in NSW for more than century, has been discovered in Sturt National Park north-west of Tibooburra.

Finding a lethal parasite's vulnerabilities

December 15, 2017

An estimated 100 million people around the world are infected with Strongyloides stercoralis, a parasitic nematode, yet it's likely that many don't know it. The infection can persist for years, usually only causing mild symptoms. ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Dec 06, 2010
Even if this weren't a failure you'd still have a federally subsidized net loss of energy on ethanol production in general.

They should rename it redherringanol.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.