Print PageIncreasing concerns about energy demand, CO2 emission and climate change urges the development of bioenergy crop system in the United States and around the world. This has led to interest in energy crops that are high yielding and have the potential to be grown on marginal non cropland, thereby providing fuel without competing with food crops. The extent to which these energy crops are environmentally and economically viable on marginal land is yet to be determined. Information is available on yields and environmental effects of growing energy crops from experimental fields and model simulations for specific sites. However, the transition to a biofuel-based energy supply on a large scale still raises many questions: (1) What is the potential productivity and spatial variability of energy crop under current climate system at the US scale? (2) What are the environmental effects of growing large-scale bioenergy crops on nutrient and hydrological cycles? (3) What are the economic potential and its spatial difference of growing bioenergy crops in the US? (4) How much noncropland is suitable for energy crop production and what is the economic and technical potential for biomass production in the US?
To address these questions, an integrated system modeling framework is being developed and applied to investigate the biophysical, physiological biogeochemical determinants of the viability of large scale cellulosic biofuel-based energy supply. This framework is developed to account for the biophysical, physiological and biogeochemical systems governing important processes that regulate crop growth including water, energy and nutrient cycles within soil-plant-atmosphere system. The energy crops considered in current framework include Switchgrass and Miscanthus. The parameters used for simulating each crop has been developed using formal estimation methods employing data sets from a north to south gradient of field trial sites in the US.
Results/Conclusions
The modeling capability will be demonstrated by estimating the potential production of Switchgrass and Miscanthus in the US under current climate system. Moreover, the impact of these energy crops on water use and Nitrogen cycle will be also assessed by the model on the US scale. Finally, the model results will be used with an economic model to assess the economic cost of producing these energy crops in the US and their economic viability on marginal land in the US.
