Stuart Preheim, an independent sales representative for Pioneer located southeast of Freeman, takes two different soil readings at depths of 2 inches and 4 inches. While official readings are taken at 4 inches, Preheim says he takes the temperature reading at 2 because that’s the depth corn is planted and is the real temperature farmers are interested in. (Matt Gade / Republic)

BROOKINGS, S.D. — As the ground thaws, farmers may be eager to get seeds in the ground, but planting too early could be a devastating mistake.

“Seeds don’t grow in the bag, right?” said SDSU Extension Agronomy Field Specialist David Karki. “But at the same time, there’s certain things we have to look at, too.”

On March 29, Karki published an article about soil temperature and germination, which warns people against planting on a pre-determined date.

According to Karki, all crops require different soil temperatures to grow properly. He said corn and soybeans are warm-temperate crops, which require soil temperatures of at least 50 and 54 degrees, although the best germination occurs at over 60 degrees.

Because of that, Karki recommended producers in southeastern South Dakota to start planting corn and soybeans between May 1 and May 15, while those in the northwest should wait until May 12 to May 26, and planting too early could cause the seeds to die, especially if the soil is wet.

“They can’t really sprout, and they’ll just stay there and eventually get some soil-born disease, some pathogen, and just rot and die off,” Karki said.

But waiting until the soil is too warm is a problem, too. Wheat germinates best in soil…