Des Moines Register: Iowa farmers face yield losses that reach 15% to 20% without a late freeze, given cold and wet spring weather that caused corn and soybeans to be planted two to four weeks later than normal. Corn is at risk of lower yields, since 20% of the state's crop was planted late. In addition to lower yields, a corn crop killed before fully maturing also requires more drying, an increased expense when farmers can least afford it.