Sustainable agriculture requires farmers to consider economic, ecological and environmental impacts of their production practices. Beyond the direct economic benefits from external inputs reduction (fertilizers and pesticides), including cover crops (CC) species in crop rotations may provide environmental services such as carbon sequestration and enhancing both soil and water quality. Research was conducted at Citra (Plant Science Research and Education Unit) and at Boyton Beach (Green Cay Farms a Community Supported Agriculture operation). Benefits of CC use were analyzed based on growth, yield and economic production cost data from a Sunn Hemp/HairyVetch-Rye/Sweet Corn (Citra 2003/04); Cowpea or Pearl Millet/Broccoli/Watermelon (Citra 2004/05); or a Sunn Hemp/Sweet Corn/Tomato or Pepper (Boynton Beach 2003-05) crop rotation. Different supplemental inorganic nitrogen (N) rates were used for both conventional and CC-based systems. Economic, energetic and environmental accounting approaches were implemented to assess the potential benefits that the use of CC may provide to these systems. Economic analysis using farm budgets methodology included marginal benefits from nitrogen supplied from either CC and/or synthetic fertilizers. Montecarlo simulation was also used for evaluating the impact of crop and nitrogen fertilizer price fluctuation on the profitability of specific systems. Energetic analysis (using Pimentel's model) was implemented to determine the fossil fuel consumption for each cropping system per unit of product leaving the system. Environmental accounting analysis (Odum's Emergy model) was used to evaluate the total amount cost-free inputs provided by the environment and the cost associated with supplemental production inputs required to ensure optimal production. Static emergy calculation was used for obtaining several indices such as emergy/yield ratio, investment ratio, emergy exchange ratio, non renewable vs. renewable ratio and empower density. Results from the three analyses are being presented and compared with data representative for conventional production systems without cover crops obtained from the literature.