Whenever summer turns to autumn, the hay harvest is at the front of farmers" minds. To mark the change of season, we"re ambling through a hayfield full of beautifully rolled bales. This particular pastoral patch is in Jutland, the agrarian mainland of Denmark that "juts" into the North Sea. But if you could—hay presto—snap your fingers and teleport to any hayfield at sunset, you"d surely see similar neat rows of dry, amber-tinted grass.