Corn is a great converter of sunlight that is being grown on some of the best land in the world and in some of the best weather. It is the grain of N. America.

On a small scale a farmer would never make ethanol to run his tractor.

Show me a link to a small farmer raising and making his tractor fuel.

Why would anyone believe that small-scale alcohol production would somehow be more efficient than large-scale, when all industrial wisdom teaches us the opposite?

who said efficiency was the concern?

You are right - as long as transportation costs are a relatively minor factor. Once motor fuel becomes really expensive, subtracting out the round trip from farm to processing plant to farm might be enough to offset those economies of scale.

Unless I am very much mis-informed, most tractors run on diesel, not gasoline. Thus, it would be biodiesel, not ethanol, that farmers would need to produce to fuel their equipment. If they do have any gasoline-powered equipment, I am pretty sure that diesel-powered alternatives exist. Farmers would be well advised to ditch their gasoline-powered equipment and switch to diesel, as they will undoubtedly realize some fuel economies, and leave better options open for themselves in the future.

I think because of the high octane content of ethanol it could be used as a diesel engine fuel with some modifications.