Hybrid poplar demonstration-scale farms were managed in Oregon, Washington, Idaho, and California to establish management practices, yields, harvesting methods, and the economics of biomass production. Yield during the 2-year establishment cycle averaged 3.5 dry Mg ha<
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year<
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increasing to 11.6 Mg ha<
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year<
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in the ensuing 3-year coppice cycle. Populus deltoides (Bartram ex Marsh.) � P. maximowiczii (Henry) varieties preformed best in Oregon during the coppice cycle with the best variety producing 18.1 Mg ha<
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year<
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, while P. �generosa (Henry) varieties maximized yields in Washington at 22.1 Mg ha<
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year<
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. P. �canadensis (Moench) varieties excelled in Idaho and California with upper yields of 13.6 Mg ha<
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year<
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and 12.9 Mg ha<
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year<
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, respectively. Stands were cut with a single-pass harvester 2 years after planting and a second time after 3 years of coppice growth
material capacity, limited by poor ground conditions, varied between 21.7 to 31.3 green Mg h<
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. Chemical composition averaged 1.87% inorganics, 7.74% extractives, 26.90% lignin, 38.07% glucan, 13.66% xylan, 1.61% galactan, 1.14% arabinan, and 2.76% mannan. Production costs (USD) projected over a 20-year rotation of six coppice cycles were $71.81 Mg<
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in Washington, $89.91 Mg<
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in Oregon, $98.76 Mg?1 in Idaho, and 179.07 Mg?1 in California. Here, land rental, establishment, crop care, harvest, transportation, and land restoration, respectively, accounted for 23%, 5%, 19%, 30%, 17%, and 6% of total feedstock cost. Farms were successfully restored to conditions existing before poplar conversion. In the absence of fertilization, increases in soil pH and decreases in nitrate-nitrogen, zinc, iron, and organic matter were consistently noted but could not be associated with poplar production alone.