"If you think you can take 1949 law and apply it in 2012 without some issues, then you haven't thought very carefully about how agriculture has changed over the last several decades," Brown said.
The cost of a farm bill looking ahead is a concern for Brown. If a short-term extension is passed and the farm bill is reopened in 2013, it will start with a new budget developed by the Congressional Budget Office.
"When I look at what I expect to see there, it is probably less money in the baseline," Brown said. "We're already talking about needing to make cuts. The cuts could seem much deeper because of a different baseline. So this notion that we could extend current law, roll into 2013 and pick up where we left off may not hold if the new baseline against which we're going to measure things has changed a lot."