Is early always better? Rethinking Soybean Planting Date
A study led by Bruce Potter and researchers from the University of Minnesota analyzed soybean planting-date experiments conducted from 1999 through 2023 at the University of Minnesota’s Southwest Research and Outreach Center in Lamberton, Minnesota. The study evaluated how planting date and soybean maturity group affected yield across growing seasons with different levels of attainable productivity.
Because precipitation was strongly associated with productivity, the researchers compared soybean responses under relatively favorable, high-productivity conditions and drier, lower-productivity conditions.
Why Does It Matter?
Early soybean planting can extend the growing season and help the crop capture more sunlight, supporting greater yield potential. However, early planting can also expose seedlings to cold soils, poor emergence, disease, and other establishment risks.
This study shows that the value of early planting is not the same across every field or growing season. Productive fields with adequate water availability are more likely to benefit from early planting and full-season varieties. In drought-prone or consistently lower-yielding fields, the additional risks and costs associated with very early planting may not provide a reliable return.
The findings support a more field-specific approach in which planting decisions consider soil conditions, water availability, historical productivity, weather forecasts, and variety maturity rather than relying on one planting date for an entire farm.
Key Takeaway
Early planting remains an effective strategy for maximizing soybean yield in productive Upper Midwest environments, particularly when full-season varieties are used. However, earlier is not automatically better in drought-prone or lower-productivity fields.
Growers may have some flexibility to plant these fields through late May without sacrificing substantial yield. Once planting moves beyond the end of May, however, the risk of rapid yield loss increases considerably.
Reference: Potter, B., Cerrudo, A., & Naeve, S. L. (2025). Is early always better? Assessing soybean planting date in Minnesota. Agronomy Journal, 117, e70076. https://doi.org/10.1002/agj2.70076
