Soybean field trial (IMAGE) Iowa State University Caption Soybeans planted at different dates are shown Sept. 20 in a field test plot at Iowa State University's Agricultural Engineering/Agronomy and Central Iowa Research Farms between Ames and Boone. Credit Tomas Della Chiesa/Iowa State University Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.