Delayed Double-Crop Soybean Planting and Maturity Groups

Chad Lee and Jim Herbek, Extension Agronomists, University of Kentucky

Double-crop soybean planting often
occurs the same day as wheat harvest.

The delayed wheat harvest is delaying double crop soybean planting. If double crop soybeans are planted by late June or early July, there is no need to adjust relative maturities. If double-crop planting ventures into the second week of July, then producers may want to reduce the relative maturity by 0.5 to 1.0 in an attempt to avoid frost damage in the fall.

As a refresher, soybean relative maturities of 4.0 to 5.0 would be considered full-season in far western Kentucky and southern Kentucky, which includes the Purchase Area and areas south of the Western Kentucky Parkway. Relative maturities from about 3.5 to 4.5 would be considered full-season in northern and eastern Kentucky, which would include the areas north of the Western Kentucky Parkway, the Central Bluegrass and Eastern Kentucky.

Soybean seeding rates should be around 160,000 to 180,000 seeds per acre for double-crop soybeans. Even though double-crop planting is delayed, that delay in planting maybe offset by the most soils this year. That moisture and the warm temperatures should allow for quicker germination and growth.