Ammonia Volatilization of Winter Spread Manure

ABSTRACT LABORATORY and field experiments were con-ducted to determine ammonia volatilization rates from winter spread manure. Factors considered were manure application rate, freeze-thaw cycles, dehydration, and the urea-ammonium conversion rate. Freezing did not increase the volatilization rate. Drying was not required for volatilization. A mathematical model describing ammonia volatilization rates from land applied manure was developed.