Jefferson Demonstration Site
Location: Jefferson, Oregon
Initial Harvest: 2013
Second Harvest: Planned winter 2017
Land Restoration: Planned summer 2017
Near Jefferson, Oregon, an 85-acre tree farm was established for the AHB project in the spring of 2012. This site is located in the Willamette Valley at an elevation 270 feet on productive agricultural land with clay loam soil. The Jefferson site averages 43 inches of precipitation per year, which is ample for good poplar growth. The site was formally managed for traditional agricultural.
The Jefferson site was established with a planting density of 1,452 stems per acre with rows aligned on 10-foot centers and three feet intervals within each row. The commercial production trials at the Jefferson site feature 11 hybrid poplar varieties. The commercial trials aim to demonstrate biomass yields, management practices, the cost of production, and harvesting logistics. The site also has multiple research plantings looking at topics such as biomass productivity, an alder intercropping trial, poplar bioenergy clonal screening trial, and colonizing the poplar with endophytes to aid in drought resistance. Researchers are also looking at wildlife populations and soil sustainability at the site. You can learn more about the research here.
Poplar growth and survival were very good during the first two growing seasons at the Jefferson site. The site’s first harvest occurred in September 2013. Pre-harvest surveys of the site showed that the trees averaged 1.4 inches in diameter and 17.5 feet in height across all clones. Survival averaged 97.8% at the end of the second year. The overall yield at the Jefferson site averaged 11.0 green tons per acre during this establishment period. Future harvests are anticipated to yield more biomass from coppice growth.