A large part of it is the ethanol mandates, pouring corn into our fuel tanks instead of feeding people and livestock.
Part of it is the drought in California, pouring water into the Pacific in the name of the smelt instead of watering crops.
Here’s a link to a .pdf detailing cost of production for corn:
http://www.extension.iastate.edu/agdm/crops/html/a1-20.html
The short version is it costs $4.25-5.10 to produce a bushel of corn.
Corn is selling right now for $4.20-4.50 per bushel.
Maybe there would be plenty of corn for free without the ethanol mandate!