The best way to obtain adequate soybean stands is to plant high quality seed in an optimum soil environment. But this year many farmers may not be able to obtain enough high quality soybean seed and some acreage may be planted with seed of lower than normal quality. Thus it will be even more important to have an optimum soil environment.
Egli, Dennis B.; Hatfield, J. L.; Hill, J.; and TeKrony, Dennis M., "The Influence of Soil Temperature on Soybean Seed Emergence" (1973). Agronomy Notes. 162.