Considerations for Soybean (Re)Planting in July

Carrie Knott, Extension Agronomist-Princeton, University of Kentucky

Considerable rainfall has accumulated throughout most of Kentucky.  Since June 1 the average rainfall for the Commonwealth is more than 3 inches above normal, with almost 2 inches of that falling in the last 7 days.  There are areas of KY that have received 10 or more inches in the last 3 weeks. Given these conditions many producers must decide whether to plant and in some cases re-plant soybeans once fields dry. 

When considering whether to plant late or re-plant two things come to mind. 
First, consider early maturing varieties.  Reducing the relative maturity by 0.5 to 1.0 can reduce the risk of fall frost damage.  Second, grain yield is reduced with each passing day.  Research at the University of Kentucky found that early July soybean plantings yielded almost 40% less than mid-May plantings and that mid-July plantings could produce 50% or less of the varieties’ yield potential.  If you are considering planting or re-planting soybeans in the Commonwealth be sure and “pencil” out these likely yield losses to ensure a profitable soybean crop can be harvested.