Given the recent bad weather, it is likely that a number of corn fields will be considered for replanting to soybean. However, before this is considered, two things must be resolved; first, how will you remove the existing corn stand and second, was there a residual herbicide treatment applied to the corn? The first can be accomplished by a number of tactics including the use of glyphosate if the hybrid is not resistant to glyphosate, tillage, or the use of a graminicide. The latter may be more of a problem if one of the herbicides used has a rotational restriction that precludes replanting to soybeans. It is critically important that you know what was applied to the corn field and check the label to make sure that soybeans are a replant option.
Iowa State University
Owen, Michael D., "Replant Options in Corn Fields" (2008). Integrated Crop Management News. 896.