The potential for dedicated energy crops to further energy security and environmental sustainability goals depends on their ability to generate farm income. Despite the best intentions of policymakers, realization of these broader goals will fall short without market incentives that make energy crop plantings economically competitive with alternative farm enterprises.
There are a number of crops suggested as feedstocks for bioenergy production, and selection will be determined by the location, sustainability criteria and biorefinery type. The crops are typically divided into herbaceous crops and short-rotation woody crops. Herbaceous crops are further divided into annual and perennial crops. Annual crops including sweet sorghum (Sorghum bicolor (L.) Moench) and forage sorghum (Sorghum vulgare Pers.) are frequently mentioned candidates for the Southeast, as are perennial grasses such as switchgrass (Panicum virgatum) and miscanthus (Miscanthus giganteus). Short-rotation woody crops that have been suggested for the Southeast include poplars, sweetgum (Liquidambar styraciflua L.), sycamore (Platanus occidentalis L.), black locust (Robinia psuedoacacia L.) and eucalyptus (Eucalyptus spp.) .
After extensive research funded by the DOE, switchgrass was selected as a model biomass feedstock [22, 41, 80]. This was based in part on high biomass yields and low input requirements. Switchgrass also provides ecosystem services such as soil conservation through decreased erosion and climate regulation through carbon sequestration. However, whether these attributes are sufficient to earn switchgrass a place among current farm enterprises across the nation remains uncertain.