Sioux City Journal: A farmers' cooperative in northwest Iowa is blaming the temporary shutdown of its corn-based ethanol plant on President Donald Trump's decision to exempt dozens of oil refineries from a federal law requiring them to blend ethanol with gasoline. Siouxland Energy Cooperative said it idled production at its plant in Sioux Center on Sept. 9. It's the first time the producer-owned plant has ceased operations for an extended period since it opened in 2000.