U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



Agricultural Research, January 2012


Work by Agricultural Research Service scientists in Florence, South Carolina, 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.

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 energy content of sunn hemp with cowpea (Vigna unguiculata)—another common regional summer cover crop—in 2004 and 2006.

The crops were grown in experimental plots near Florence, and both were harvested on the same day, three times in each study year. The last harvest in both years was conducted right after the first killing freeze of the season.