Miscanthus, a fast-growing grass often grown as a biofuel, is now planted on six military sites, from Kansas to Kazakhstan, in a three-year NATO-run effort to clean up contaminated soil. At a conference earlier this month at Kansas State University, researchers reported that the grass stabilizes contaminants in the soil, preventing them from escaping into the air and water, and then gradually absorbs them.
In addition to biofuel, the researchers involved in the project are also exploring other bioproducts, such as paper and building materials, that can be made from miscanthus.
Of the six sites, a roughly 1-acre plot at Ft. Riley, the U.S. Army base in Kansas, is the most advanced, with the third crop of miscanthus planted last spring. The soil there is contaminated with lead from practice bullets, and land managers first addressed the contamination by sieving of the soil, which picked up the largest bullet remains. Lead is found naturally in soil at levels between 15-40 parts per million (ppm). Levels in the Ft. Riley miscanthus plot are about 1,000 ppm.
Miscanthus’s great strength as a phytostabilizer makes it a good fit for degraded military sites that will take years to restore, the researchers said. In addition to the Ft. Riley site, the project includes contaminated military land in the Czech Republic, Ukraine, and Kazakhstan.
“In our project the goal is two-fold. First, to increase the environmental security of the former military sites by means of phytostabilization” says Valentina Pidlisnyuk, an environmental chemist at Jan Evangelista Purkyne University in Czech Republic, and one of the leaders of the project. “The other goal is to process miscanthus biomass to energy, which particularly for Ukraine is a major problem after the beginning of the war with Russia.” Pidlisynuk says that planting miscanthus will replenish the soil with carbon, nitrogen and humus and prevent erosion. She adds that the project already has municipal governments in the Ukraine that are interested in using the miscanthus biomass.
Larry Erickson, a chemical engineer at Kansas State who co-leads the project with Pidlisnyuk, hopes that the gradual absorption of lead by the miscanthus, coupled with other remediation efforts, will restore the Ft. Riley soil and serve as a model for other contaminated sites. “If we can take the marginal soils and grow miscanthus for twenty years, it would be more productive for crops like wheat after that,” says Erickson.