Senator Joni Ernst.

Iowa’s Chuck Grassley and Joni Ernst have joined 14 of their colleagues in the Senate to co-sponsor legislation that would boost U.S. producers of biodiesel.

Republican Senator Chuck Grassley and a senator from Washington state who is a Democrat are the lead sponsors of the legislation. It would extend the tax credit for biodiesel for three more years. More significantly, though, the credit would go to the producers of biodiesel.

Today, the credit goes to the companies that blend the soybean-based fuel into diesel made from petroleum. Grassley, Ernst and the other 14 senators say the move is important, because foreign imports of biodiesel are rising dramatically and the current biodiesel credits are supporting those imports. In many cases, the biodiesel shipped into the U.S. gets foreign subsidies, too. Grassley calls that “double-dipping.”

In the past quarter alone, biodiesel imports were 10 percent above levels during the first three months of 2016.

Iowa is the nation’s leading biodiesel producers. According to the Iowa Renewable Fuels Association, biodiesel accounts for nearly half a billion dollars of Iowa’s Gross Domestic Product,with nearly 4000 Iowans employed in the biodiesel industry.