Bad forecast for cellulosic ethanol?

A new study suggests that cellulosic ethanol will never take off because the subsidies necessary to get farmers to grow switchgrass rather than food crops would be prohibitively high. Wheat prices have already risen 83% in the past year to record highs, and biofuels are cited as one reason:

Demand for alternative energy sources has led farmers to sow less wheat and convert land to crops such as corn, sugarcane and rapeseed, that can be turned into biofuels.

Ethanol, diesel and other liquid fuels can be made from processing plant material.

But this means there is less land for growing food crops.

Wheat prices may come down as high prices convince farmers to devote more land to the crop, but this takes time.

And even if there wasn't a problem with competition for arable land, this approach still doesn't get around the basic problem of dwindling fossil fuel supplies: each year we use the equivalent of multiple years worth of sunlight reaching the Earth. And if that's the case, no crop is ever going to be able to replace a major portion of our energy use.

My guess is that cellulosic ethanol--or any other biofuel--will likely be only a small part of our energy future...