Ag leaders and Iowa lawmakers applauded last week’s approval of a U.S.-Japan trade deal by the Japanese parliament. The trade deal, which is set to begin Jan. 1, is expected to lower or eliminate tariffs on $7.2 billion in U.S. farm exports. 

“This is a big win for farmers, and we hope it’s the first of many trade deals to be approved that will open markets and level playing fields for American agricultural exports,” said Zippy Duvall,...