Cover Crops (IMAGE) Penn State Caption Agricultural scientists, like Penn State researchers, have been experimenting with cover crop mixtures (like the one shown growing at the Russell E. Larson Agricultural Research Center) to determine which ones best limit the runoff of nutrients and provide the most ecosystem services. Credit Mitch Hunter Usage Restrictions Non commercial use 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.