Iowa leads the nation in egg production and processing with close to 60 million laying hens at 65 locations around the state. That many chickens produce a lot of ammonia-rich manure, which needs to be managed to protect air and environmental quality. A demonstration project that wrapped up field monitoring this spring shows promise in reducing the ammonia coming from those operations. Hongwei Xin, agricultural and biosystems engineering professor who directs the Egg Industry Center, leads a research team that has been testing how two alternative diets affect ammonia output.