Farmer Tending to an Agricultural Crop (IMAGE) U.S. National Science Foundation Caption Agricultural crops are studied in experiments at NSF's Kellogg Biological Station LTER site. Credit Julie Doll, NSF KBS LTER Site 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.