COLLEGE PARK, MARYLAND, U.S. — The University of Maryland-College Park (UM) and Bowie State University, Bowie, Maryland, U.S., announced on Feb. 25 that a team of researchers representing both universities is working on ways to turn poplar trees into high-yield crops for biofuels including ethanol.

The hybrid trees would be grown on plantations and harvested without affecting existing woodlands.

The study is funded by a $3.2 million, four-year grant from the National Science Foundation's Plant Genome Research Project, which supports research on plants seen as having economic and agricultural importance. Using the recently completed poplar genome, the researchers are focusing on ways to improve the tree's nitrogen processing capability, which will enhance its growth rate and feasibility for use in fuel production.

For poplar to be truly effective as a biofuel source, its growth cycle needs to speed up and become more efficient, according to the researchers. One of the keys to doing so is to understand how it stores and cycles nitrogen, since nitrogen is an important factor in the growth and productivity of trees and crops.

The fertilizers that help produce big harvests are rich in nitrogen but are expensive and must be reapplied each year. Poplar is a perennial plant, capable of pulling nitrogen from its leaves, storing it through the winter, and redistributing it in the spring. A poplar tree is also capable of regrowing itself from its roots after being cut and may go through several cycles of growth and harvest throughout its life before a new tree needs to replace it.

"Both the growth in the spring and regrowth from roots after the stems are harvested depend on the availability of stored nitrogen," said Gary Coleman, lead researcher and associate professor of plant science and landscape architecture at UM's College of Agriculture and Natural Resources. "The data we collect will allow us to understand mechanisms of nitrogen cycling, determine how to increase the rates of the cellular reactions, and identify the genes that play a crucial role in the process. Eventually, we should be able to breed a variety of poplar with a more efficient nitrogen process, optimized for growth and rapid maturity."