Falling profit margins for the $40 billion U.S. ethanol industry may cause some companies to scale back production in 2015. Bloomberg News Tumbling oil prices are bringing unwelcome tidings to one of the U.S. Farm Belt’s hottest industries. Ethanol makers are bracing for a drop in earnings as cheap crude pushes down the prices they fetch from refiners to blend the corn-based fuel additive into gasoline. Ethanol producers also face a recent jump in the price of corn, their main raw material. Falling profit margins for the $40 billion U.S. ethanol industry may cause some companies to scale back production in 2015, analysts and industry executives say. Still, many observers think ethanol demand may remain steady or even rise if cheap gasoline spurs U.S. motorists to drive more, tempering the hit to ethanol earnings. Crude-oil prices slid 20% in December to about $53 a barrel and fell 46% […]