High levels of ammonia in poultry farms is an old time issue of major concern to stake holders that has continued unabated. Poultry producers are under pressure from interested groups and neighbors to reduce ammonia emissions for health and environmental reasons. Inhibition of putrefying and ammonifying bacteria in poultry manure is therefore critical to reduce NH3 volatilization. Ferrous sulfate heptahydrate at concentrations of 2%, 5% and 10% was used to lower manure pH in order to inhibit the activities of putrefying and ammonifying bacteria and hence reduce ammonia volatilization. The various concentrations of the ferrous sulfate heptahydrate (FeSO4.7H2O) were added to about 300g each of the poultry waste and thoroughly mixed together using a mixer. pH, microbial load count and odors were evaluated according to standard methods. Results showed that Ferrous sulfate hepta hydrate at 10% lowered the poultry manure pH from an initial 7.68 to 3.78 in 7days, and 4.60 at the end of 35 days of treatment respectively. Total coliform bacteria in 10% were reduced from 2.85 x 103 CFU ml-1 to 0.29 x 101 CFU ml-1. The pH ranges are in agreement with the value of 5.0 recommended to fix ammonia in stored animal waste, supported by the fact that a positive correlation exists between manure pH and ammonia volatilization. Panelist results for odor levels were equally impressive at 10% concentration.
