The Iowa Soybean Association On-Farm Network’s website is loaded with in-depth analysis of images (www.isafarmnet.com/RemoteSensing/RemoteSensing.html) and a gallery of fascinating aerial photos with explanations of what they reveal. There are examples of nitrogen and moisture stress, insect and storm damage, field variations and equipment errors. You can even see an image of a cornfield studded with mysterious round circles caused by – believe it or not – wallowing bears.