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⁻¹ year⁻¹ increasing to 11.6 Mg ha⁻¹ year⁻¹ 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⁻¹ year⁻¹, while P. ×generosa (Henry) varieties maximized yields in Washington at 22.1 Mg ha⁻¹ year⁻¹. P. ×canadensis (Moench) varieties excelled in Idaho and California with upper yields of 13.6 Mg ha⁻¹ year⁻¹ and 12.9 Mg ha⁻¹ year⁻¹, 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⁻¹. 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⁻¹ in Washington, $89.91 Mg⁻¹ in Oregon, $98.76 Mg⁻¹ in Idaho, and $179.07 Mg⁻¹ in California. 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.

在俄勒冈州，华盛顿州，爱达荷州和加利福尼亚州对杨树混合示范规模的农场进行了管理，以建立管理规范，产量，收获方法以及生物质生产的经济性。在随后的3年小灌木林周期中，在2年生长期中的平均产量为3.5干Mg ha - ¹年^-1，增至11.6 Mg ha - ¹年^-1。美洲黑杨（巴特拉姆前沼泽。）× P.藓（亨利）品种的最佳品种生产18.1镁公顷的矮林周期中预制在俄勒冈州最好的^-1年^-1，而P。×属（亨利）品种在华盛顿州的最高产量达到22.1 Mg ha - ¹年^-1。P. × canadensis（Moench）品种在爱达荷州和加利福尼亚州均表现出色，最高单产分别为13.6 Mg ha - ¹年^-1和-12.9 Mg ha - ¹年^-1。种植后2年用单次收割机切割林分，而小灌木林生长3年后用第二遍切割林分。受恶劣地面条件限制的材料容量在21.7至31.3绿色Mg h ^-1之间变化。化学成分平均为1.87％的无机物，7.74％的提取物，26.90％的木质素，38.07％的葡聚糖，13.66％的木聚糖，1.61％的半乳聚糖，1.14％的阿拉伯聚糖和2.76％的甘露聚糖。预计在六个矮林周期为20年转生产成本（美元）是$ 71.81镁^-1在华盛顿，$ 89.91镁^-1在俄勒冈州，$ 98.76镁^-1在爱达荷州和$ 179.07镁^-1在加利福尼亚。土地租金，建立，作物护理，收割，运输和土地恢复分别占原料总成本的23％，5％，19％，30％，17％和6％。农场已成功恢复到杨树转换之前的现有条件。在没有施肥的情况下，土壤pH值的增加以及硝酸盐氮，锌，铁和有机物的减少一直被注意到，但仅与杨树的生产无关。