"It is unconscionable that we don't have a farm bill," Vilsack said in an interview aired on CNN's "State of the Union." "This is just historic."
The bill, which gives farmers price protections and subsidies, expired Sept. 30, CNN said.
"When you consider what rural America does: It provides most of the food, a lot of the water, almost all of the energy and fuel as well as many, many jobs connected to what happens in rural areas," Vilsack said.
If Congress does not act soon, customers could see the price of milk nearly double as a dairy subsidy expires Jan. 1, Vilsack said.
"Across the board, in virtually every aspect of our economy and society, there is an impact," Vilsack said.
House Speaker John Boehner, R-Ohio, said in September that the House would address the expired bill after the election, however, this has yet to happen.