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... The 50° mark is considered the minimum for corn and soybean seeds to germinate, though as the University of Nebraska-Lincoln pointed out, corn can withstand soil temperatures down to 40°F without damage.

The higher the temperature, the faster crops develop and emerge from the soil. According to Iowa State University, corn planted at soil temperatures at 50°F take 21 days for emergence, while it only takes seven days at 70 degrees.

Soil temperature therefore affects development and consistency in stands. Small differences in temperature can have larger effects in total corn stands at lower temperature than at higher temperature. On the other hand, planting early has also been shown to increase yields for various reasons, but especially because the plant can capture more sunlight for a longer period of time. ...