Shawn P. Conley, State Soybean and Wheat Extension Specialist

John Gaska, Outreach Specialist

University of Wisconsin, Madison

Andrew Robinson, Graduate Student, Purdue University

 

Planting date is one of the most important and least expensive cultural considerations that impacts soybean yield. As adverse weather delays corn and soybean planting, it is important to know the yield cost of these delays for both marketing and management considerations.  Research conducted at the University of Wisconsin, Arlington Research Station has shown an average yield loss of 0.4 bu per acre per day when soybean planting is delayed past the first week in May (Figure 1). Yield loss in delayed plantings can be attributed to decreased pod number per acre (Robinson, 2008). Robinson (2008) found that pod number was the most important yield component in March, April, and early May planting dates. In late May and early June plantings, seed mass played an equally important role in determining yield. This indicates that delayed plantings of soybean can partially compensate for reduced pod number per acre through increased seed size.          

 

Figure 1. Planting Date Effect on Soybean Yield at Arlington WI in 2006 and 2007.

 

 

 

Andrew Robinson, 2008. Early planting influence on yield, protein, oil and seed vigor on indeterminate soybean. M.S. Thesis.