The president said he hoped lawmakers get an earful from their constituents during the five-week recess away from Washington and that they reconvene on September 10 prepared to complete work on a farm bill "immediately."

Food stamps for the poor would see their biggest cut, $16 billion, since the 1990s in the House farm bill. Democrats oppose those cuts and fiscal hawks among Republicans say the bill, which raises crop support prices, needs more cuts throughout. The Senate bill would cut food stamps by $4 billion.

"Congress needs to pass a farm bill that will not only provide important disaster relief tools but also make necessary reforms and give farmers the certainty they deserve," said Obama in his first remarks on the farm bill in weeks.