PIERRE, S.D.—Even as farmers in central South Dakota are replanting fields wrecked by hail storms 10 days ago, harvest has started, too, as the first bushels of winter wheat have come off. Last week, Tom Young of Onida was out planting sunflowers on ground where just a couple months earlier he had planted field peas. The storm consisting of high winds, heavy rains and lots of hail cut the field peas down. It was part of a 50-miles-long...