How much does the US spend each year in farm subsidies?

About 10 to 15 billion dollars per year -- about 4/10ths of one percent of the US federal budget. Just for comparison, the Supplemental Nutrition Assistance Program or SNAP (formerly called food stamps) spent over $80 billion in 2012.

For those looking to save the US government some money, I would suggest the $750 billion dollars in waste alone in the Medicare program.