Exceptionally High Yields and Soil Carbon Sequestration Recorded for Giant Reed in Alabama.

Giant reed has been extensively evaluated as a dedicated cellulosic energy crop in southern Europe, with very favorable results. Therefore, efforts to commercialize it are being stepped up in countries like Itally, Greece, France, Spain and Portugal. The crop has also been evaluated for cellulosic biomass production in China, and in the USA, by Washington State University and by Auburn University in Alabama, from 2000 to 2009. In this experiment, total biomass yields were measured annually in a replicated small plot study by harvesting in fall or winter, and rhizome accumulation over a 10-year period was estimated by harvesting rhizomes in 2009. Average dry biomass yield over a 9-year period in Alabama was 33.6 Mg ha^-1, with no nitrogen fertilizer applied in the last 8 years, and no irrigation. Yield of Alamo switchgrass cut twice a year in an adjacent experiment over the same period was 24.5 Mg ha^-1. Dry rhizome accumulation for Giant Reed was 93.7 Mg ha^-1, indicating that soil carbon sequestration for this crop is three to four times higher than that measured for switchgrass in a previous study. Several private companies, including TreeFree Biomass Solutions in Seattle, and White Technology in the Southeast, are in the process of commercializing Giant Reed for cellulosic biomass production. However, irresponsible attempts to use the crop for erosion control in riparian sites in southern California, and along the Rio Grand in Texas, have led to the plant getting out of control in these watersheds. This has created exaggerated perceptions in the US that there is a high risk involved in developing the crop for commercial cellulosic biomass production.