081319 404 Iowa’s senior senator has some harsh words for the Environmental Protection Agency. That’s because of its decision to release many small oil refineries from their obligations to blend ethanol into gasoline. The past few days have dealt multiple blows to corn farmers: on Friday, EPA granted 31 so-called “hardship” waivers. And Monday, a prediction from the Agriculture Department showed declining demand for corn because ethanol production is down. The Renewable Fuel Standard, or RFS, is