Growing concern about climate change and energy security has led to increasing interest in developing domestically available renewable energy sources for meeting the electricity, heating and fuel needs in the United States. Illinois has significant potential to grow perennial grasses that can provide bioenergy. Recent research on miscanthus has shown that this low-input perennial may have biomass yields that are twice that of switchgrass and corn. Land requirements from growing biomass crops compete with existing profitable land uses, which in the case of Illinois, is primarily in row crop agriculture. This study examines the conditions of switching land from row crops to energy crops which are expected to vary across the landscape in Illinois, depending on soil quality and climatic conditions. To find the optimal land allocation among competing uses we will use spatial dynamic modeling tools combined with data from Geographic Information Systems (GIS) on land quality, climate and land use. The Spatial Modeling Environment (SME) allows inclusion of spatially enabled dynamic models to combine system-dynamics and agent-based modeling approaches. Four major crops are compared, including corn, soybeans, miscanthus, and switchgrass.