Switchgrass Yield Factors (IMAGE) American Society of Agronomy Caption Data from field trials were compiled to better understand the role of soil, climate, and crop management factors in determining yields across the United States. Credit Wullschleger, S. D. Usage Restrictions None License Licensed 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.