The fuel used for turning the soil, planting the seeds, spraying harvesting, drying. The energy used to make the fertilizer. Water and energy to irrigate. Then

The fuel used for turning the soil, planting the seeds, spraying harvesting, drying. The energy used to make the fertilizer. Water and energy to irrigate. Then the refining and transportation of the alchohol. Corn takes a lot of input energy. I believe that sugarcane is closer to break even as it requires less upkeep.