Sunn hemp shows promise as biofuel source

Jan 04, 2012 By Ann Perry
Sunn hemp shows promise as biofuel source
The tropical legume sunn hemp (Crotalaria juncea) could be a good biofuel crop for farmers in the southeast, according to new ARS research. Credit: Forest & Kim Starr.

Work by scientists at the U.S. Department of Agriculture (USDA) suggests that farmers in the Southeast could use the tropical legume sunn hemp (Crotalaria juncea) in their crop rotations by harvesting the fast-growing annual for biofuel. The study, which was conducted by Agricultural Research Service (ARS) scientists in Florence, S.C., supports the USDA priority of finding new sources of bioenergy. ARS is USDA's chief intramural scientific research agency.

ARS agricultural engineer Keri Cantrell, agronomist Philip Bauer, and environmental engineer Kyoung Ro all work at the ARS Coastal Plains Soil, Water, and Plant Research Center in Florence. They compared the of sunn hemp with cowpea (Vigna unguiculata), another common regional summer , in 2004 and 2006.

Both crops were grown in experimental plots near Florence and were harvested on the same day three times in each study year. The last harvest for both years was conducted right after the first killing freeze of the season. The scientists measured potential energy production of both via direct combustion. This provided the feedstocks' higher heating value (HHV), which indicates how much energy is released via combustion.

In 2004, when there was ample rainfall, the resulting sunn hemp biomass yield totaled more than 4.5 tons per acre. This is equivalent to 82.4 gigajoules of energy per acre, close to the energy contained in 620 gallons of gasoline and well in the ballpark of other bioenergy crops, which have yields of anywhere from 30 to 150 gigajoules per acre.

The HHV for sunn hemp biomass exceeded the HHV for , bermudagrass, reed canarygrass and alfalfa. Although reduced rainfall resulted in lower hemp biomass yields in 2006, sunn hemp's HHV for both study years was 4 to 5 percent greater than the HHV of cowpeas.

Results from the study were published in 2010 in Biomass and Bioenergy.

Explore further: Improving the productivity of tropical potato cultivation

More information: Read more about this research in the January 2012 issue of Agricultural Research magazine.

Provided by USDA Agricultural Research Service

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Can hemp help the everglades?

Aug 06, 2007

Within Southern Florida, soil and water conditions indicate potential for leaching from the use of atrazine-based herbicides in corn crops. Scientists from USDA-Agricultural Research Service (ARS) and University ...

Using biochar to boost soil moisture

Nov 08, 2011

Scientists at the U.S. Department of Agriculture (USDA) are leading the way in learning more about "biochar," the charred biomass created from wood, other plant material, and manure.

Swedish hemp farmer wins green prize

Nov 30, 2007

A Swedish hemp farmer was given an environmental prize in his local community for his efforts to fight a ban on the growing of industrial hemp.

New Switchgrass Germplasm Collected in Florida

Nov 26, 2009

(PhysOrg.com) -- Agricultural Research Service (ARS) scientists and cooperators have collected 46 new populations of switchgrass in Florida, adding valuable new accessions to the germplasm collection of this ...

Recommended for you

Building better soybeans for a hot, dry, hungry world

8 hours ago

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

Gene removal could have implications beyond plant science

8 hours ago

(Phys.org) —For thousands of years humans have been tinkering with plant genetics, even when they didn't realize that is what they were doing, in an effort to make stronger, healthier crops that endured climates better, ...

Chrono, the last piece of the circadian clock puzzle?

22 hours ago

All organisms, from mammals to fungi, have daily cycles controlled by a tightly regulated internal clock, called the circadian clock. The whole-body circadian clock, influenced by the exposure to light, dictates the wake-sleep ...

User comments : 0

More news stories

Adventurous bacteria

To reproduce or to conquer the world? Surprisingly, bacteria also face this problem. Theoretical biophysicists at Ludwig-Maximilians-Universitaet (LMU) in Munich have now shown how these organisms should ...

Revealing camouflaged bacteria

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so cal ...

How kids' brain structures grow as memory develops

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring ...

Gate for bacterial toxins found

Prof. Dr. Dr. Klaus Aktories and Dr. Panagiotis Papatheodorou from the Institute of Experimental and Clinical Pharmacology and Toxicology of the University of Freiburg have discovered the receptor responsible ...