6-4 (IMAGE) American Society of Agronomy Caption Lead author of the study Dr. Gurbir Singh collecting hairy vetch cover crop biomass samples before termination of cover crops. Credit Gurpreet Kaur Usage Restrictions For use with this story only. 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.