An apparatus is disclosed for applying a chemical, such as an ammonia control chemical, in an animal house. The apparatus includes spreading apparatus adapted to be installed at an elevated position in the animal house and adapted for spreading the chemical onto the floor in the house. The apparatus also includes feeding apparatus adapted for feeding the chemical from a supply to the spreading apparatus. A method of controlling ammonia emissions from an animal agriculture operation includes applying an ammonia control chemical during both the early part and the late part of the grow out of the animals so that the chemical contacts ammonia from animal waste and reduces or prevents its emission into the air.