Corn Canopy (IMAGE) American Society of Agronomy Caption A student uses the GreenSeeker active canopy sensor to collect canopy reflectance data. The collected data will help determine the crop's nitrogen status. Credit Guohui Feng Usage Restrictions Please use with 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.