Improved compositions are disclosed that inhibit ammonia volatilization from poultry litter and other animal enclosures. In some variations, a composition for use in reducing ammonia generation in animal enclosures comprises metal sulfate, an organic acid with pKa of about 3 or higher, and optionally a buffer. In some variations, a composition for use in reducing ammonia generation in animal enclosures comprises metal sulfate, an inorganic acid with pKa of about 1 or higher, and a buffer. A method of reducing ammonia concentration in an animal enclosure (e.g., a chicken house) includes introducing any of the compositions described herein. In some embodiments, the animal enclosure is a chicken house. The ammonia concentration may be maintained below 50 ppm NH3, preferably below about 25 ppm NH3.
