Biofuel crops are like any plants; they need the right combination of sunlight, water, nutrients and time to grow. And like houseplants or backyard garden vegetables, some of these crops do better in certain regions than others.
This can cause a major dilemma for advocates of plant-based fuel. A biofuel farmer in an arid region such as the American Southwest would have to invest heavily in irrigation to grow enough corn to produce an economically viable quantity of ethanol [source: McKenna]. The alternative, having a diesel-powered truck haul fuel in from another region, presents transportation costs -- and significant emissions -- that limit the fuel's advantage over petroleum diesel [source: Pimentel].
Further complications develop when biofuel for one nation is produced in another nation. Palm oil plantations in Indonesia, for example, have come under fire for causing massive deforestation and significant greenhouse gas emissions. Their purpose? To produce clean biodiesel for European drivers. This outsourcing of biofuel production simply moves the pollution, rather than eliminating it [source: Rosenthal].