Breaking News-RTRS-Slow corn seeding in eastern US Midwest may add soy

CHICAGO, May 5 (Reuters) - Grain planting this spring in the United States, the world's largest exporter, is turning into a tale of two Corn Belts -- with one possibly seeing more soybeans than expected in the ground by June, experts say.
As a rule of thumb, corn not in the ground by May 15 in Iowa and Illinois tends to yield a bushel an acre less per day due to the shorter growing season and autumn frosts. So after that date, farmers often switch soy, a faster-growing crop.