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The development of a cellulosic biofuels industry is likely to involve the cultivation of switchgrass (Panicum virgatum L.) monocultures throughout the U.S. Switchgrass fields will likely displace pastureland, woodland, or Conservation Reserve Program (CRP) land rather than highly productive cropland. This planting approach may further diminish natural habitats throughout the Northern Great Plains. Furthermore, marginal and ex-arable land is often variable in topography and soil condition. Natural grassland communities are also heterogeneously distributed along a topographic gradient according to habitat niches. A diversified feedstock planting that emulates natural communities may retain or increase field productivity with greater plant diversity. Diverse polycultures with more numerous functional groups (warm & cool season grasses and forbs) and greater structural diversity would provide numerous ecosystem services such as wildlife habitat, reduced runoff, and carbon sequestration. This research differs from prior feedstock evaluations in that multiple, polyculture mixtures will be planted according to species adaptations along environmental gradients. The experiment evaluated the performance of 4-species polycultures from 3 functional groups (warm & cool season grasses and forbs) grown with switchgrass at 3 slope positions (foot, mid, shoulder) and at different switchgrass seeding ratios (low, medium, high). This experiment hypothesized that polycultures optimized for slope position and seeding ratio will outyield switchgrass monocultures grown at the same slope position. Mixtures were also evaluated for (1) establishment success, (2) seasonal biomass yield, and (3) relative efficiency in resource utilization relative to diversity. Findings were from data collected during the first production year (2014). This research will aid producers in balancing production with environmentally beneficial farm practices using the selective planting of polyculture feedstocks.