Switchgrass, mixed grass research projects advance

By Susanne Retka Schill
Switchgrass and other mixed prairie grasses are being given a closer look in two northern plains projects that received additional support this winter.

South Dakota State University's work on switchgrass got a boost from a new agreement with California-based Ceres Inc. The cooperative, multi-year program will focus on developing higher-yielding switchgrass cultivars adapted to northern latitudes. SDSU plant breeder Arvid Boe will lead field and greenhouse research, which will involve crossbreeding and selections supported by Ceres technology that makes the selection process more efficient and predictable. University researchers will also study genetic diversity in the perennial grass species, among other objectives.

Boe believes switchgrass can be competitive with conventional crops, especially on semiarid land in South Dakota and Nebraska. "Switchgrass is tolerant of a wide range of environmental conditions, and compared with many other perennial grasses and conventional crop plants, it produces relatively large amounts of biomass under both good and poor growing conditions," he said.

Separately, the Central Grassland Research and Extension Center in Streeter, N.D., received $40,000 in funding from the North Dakota Agricultural Products Utilization Commission for the center's 10-year study on biomass grasses. The funding will expand the project from grass trials to economic analyses of what a farmer would need to receive for a cellulosic crop to compete with other, more traditional crops. The project started with funding from the North Dakota Natural Resource Trust, according to Paul Nygren, director of the CGREC. "There's a lot of concern about what happens to our perennial grasslands as the pressure comes from biofuels," he explained.

The first grasses for the 10-year study were seeded in the spring of 2006 at five locations in central and western North Dakota that would correspond with mixed-grass prairie and short-grass prairie regions. The plots include various pure stands and combinations of switchgrass, tall and intermediate wheatgrass, big bluestem, and wild rye. There are also two mixes used on Conservation Reserve Program acres, one with tall and intermediate wheatgrasses alone, and one with the two wheatgrasses, alfalfa and sweet clover. Nygren hopes to raise additional grant funds to pay for sample analysis in a cellulosic digester to complement the analyses to be done in the forage laboratory.

Acknowledging that biomass yields in semiarid regions may be too low for large cellulosic ethanol plants, Nygren wants to study the feasibility of smaller-scale pyrolysis units. He's working with a potential cooperator now to add a pyrolysis study that would test the potential yield from the various grass mixes.