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Cooperators needed for planting date research

Article cover photo
The On-Farm Network is looking for participants for a planting date trial. They are looking at planting later-maturing soybeans at earlier dates for higher yields. (Photo: Joseph L. Murphy/Iowa Soybean Association)

By Scott Nelson, On-Farm Network® Director

The On-Farm Network® at the Iowa Soybean Association (ISA) represents research for farmers by farmers. The team works directly with farmers to conduct research on their fields, exploring topics of interest for both the farmer and the researchers.

The On-Farm Network is seeking cooperators for a new study to help test the notion of late maturing soybean varieties that are planted early. Optimum planting date for soybeans in Iowa is believed to be between the last week of April to the first week of May. Yet many questions remain about which soybean maturity varieties to use when planting early or late.

Crop physiologists assert that early planting dates of later-maturing soybean varieties are a means to increase soybean yields. Some farmers working on other trials with the On-Farm Network have reported as much as an increase of 10 bu/acre when using this practice. Theoretically, the combination of later maturing varieties with an early planting date captures the most sunlight, possibly resulting in greater harvestable yield. 

For farmers participating in this study, the ISA researchers ask them to plant in mid- to late-April a later-maturing soybean variety for their area along with a normal-maturing variety. Then three weeks later, plant the same varieties in the same field. 

Cooperators will receive a $500 stipend for the extra effort of planting a second time. The major benefit for participants is a new insight into soybean variety selection for their farms as well as a better understanding of the impact early planting dates can have on their profitability. 

If you are interested in participating in this trial, please contact your ISA regional agronomist or send an email:

Contact Scott Nelson at

For media inquiries, permission to republish articles or to request high-res photos, please contact Katie James, ISA Public Relations Manager at © 2020 Iowa Soybean Association. All rights reserved.