It is well known that planting date plays a key role in determining yield potential in corn and soybean. Long-term University of Minnesota trials demonstrate, for example, that corn yield is usually optimized when corn is planted from April 25 to May 10. Long-term data also show that soybean yield is optimized when planting occurs around May 1. Planting earlier than these guidelines rarely leads to greater yields but does increase risk of stand loss from frost or cool conditions after planting. This can lead to reduced yield or even the need to replant. Soil conditions at planting are...