Think Food's Spendy Now? The Flood Just Made It Worse. . . Sixteen percent of Iowa farms have been destroyed and their entire crops demolished following the severe flooding. The devastation has in turn caused record high market prices of corn and soybean products. The prospects of the smaller amounts of grain yields shocked the market where corn prices rose to nearly 8$/bushel; four times the amount of its usual price and a new record. World corn prices have now risen to 90 percent higher levels than just one year ago.