What is the fine-grained topic of the following text: ST. LOUIS (AP) - As the rain-swollen Mississippi River carried on its plodding retreat Friday, western Illinois farmer Joe Zumwalt wasn’t complaining about the flooding that wound up swamping a hundred or two of his 3,500 river-bottom acres of corn and soybeans. Only return the topic.
Flooding impact on farmer's corn and soybean crops in western Illinois