Researchers Look at Biomass Potential of Black Locust Plant

Researchers from the Energy Biosciences Institute (EBI) at the University of Illinois are taking a closer look at Robinia pseudoacacia, a short-rotation crop commonly known as black locust, because of its higher biomass yield and faster growth compared to other candidate woody plant species.

Initial study on black locust, which grows well in the Midwestern region, showed its ability to regrow rapidly with multiple stems after coppicing or cutting the plants back to single stem just a few inches from the ground. Last season, the researchers observed that the plants were almost equivalent to the first two years' growth since they were coppiced in February 2012. This spring, they recorded a yield of 12 to 13 mega grams per hectare, which exceeded what was produced over the first two years' growth. This exceptional rapid growth of black locust would allow harvesting every 2 years rather than every 3 to 5 years, which means a faster payback for producers.

The biomass potential of black locust must be evaluated to qualify it as a bioenergy crop. The researchers are now evaluating commercial black locust germplasm from different sources across 8 states in the U.S. to see if they can isolate faster growing ones. They have also obtained seeds from international sources such as Afghanistan, Uzbekistan and Iran, and from a remediated quarry area in the U.S. where they found native black locust growing. The researchers will evaluate whether to coppice the plants at the end of 1 or 2 years.