Biodiesel plants in Iowa produced a record 56.7 million gallons of the fuel in the second quarter, the Iowa Renewable Fuels Association announced Thursday. The association credited "the combination of a strong federal renewable fuel standard and reinstatement of the federal biodiesel blenders tax credit" with enabling producers to achieve the new record, which represented a 3.3 percent increase in production over last year's second quarter. The association wants the biodiesel blenders tax credit extended. It's set to expire at the end of 2013. The association also is lobbying Congress and the U.S. Environmental Protection Agency to lower or eliminate the renewable fuel standard.