The results from the weekly U.S. Drought Monitor map are in, and it doesn't look like it's getting better.  75 percent of Iowa, the nation's biggest corn producer, is enduring extreme or exceptional drought, which are the two worst classifications. That's up roughly 10 percent from last week. This won't affect the corn crop, but it could hurt winter wheat. Nearly 98 percent of Nebraska still falls into the two most severe drought categories. Drought in the rest of the nation hasn't changed.