Across the Midwest, a cold and wet spring has slowed the pace of corn plantings — as of Monday 19 percent was in the ground versus the usual 28 percent for this time of year, according to the U.S. Department of Agriculture. The slow start could slash yields. In the future, hotter and drier conditions due to global warming could also put a dent in corn yields, according to a new study.

The research is based on field data from more than 1 million federal crop insurance records between 1995 and 2012 and correlated with fine-scale weather data. It shows that while corn yields in the Midwest have steadily risen, the staple grain is also growing more sensitive to drought. About 80 percent of the corn grown in the Midwest is dryland. If it doesn’t rain, there is no water.