Predication of Ammonia Emission From Poultry Layer and Dariy Houses Using an Alternative Mass Balance Method

The alternative N/Ash (N/A) and N/Phosphorus (N/P) mass balance method were used to predict upper limit ammonia emission rate from three manure-belt layer houses and three free stall dairy houses in Ohio. The mass balance equations have been developed to eliminate the needs for tracking manure flow rate to obtain accurate ammonia estimation. Results show that this alternative mass balance method can estimate ammonia emission from manure-belt poultry layer houses and free stall dairy houses effectively. NH3 emission rate from manure belt poultry layer houses with manure removal every 3.5 to 5 days was 0.03-0.31 g NH3 bird-1day-1 using N/A mass balance method. These results agrees well with the ammonia emission values published in the previous literatures (0.03-0.62 g NH₃ bird^-1day^-1), but were lower than the NH3 emission rate (0.10-0.86gNH₃ bird^-1day^-1) measured using continuous monitoring systems. For the sand bedding dairy houses with manual and mechanical manure scrapers, the ammonia emission rate was 36.45-169.22 g NH₃ cow¹day^-1 using N/P method. The results using N/P method agreed with those from published literatures (35.89-152.05 g NH₃ cow¹day^-1) very well. For the dry manure bedding dairy house with flushing water to remove manure, the ammonia emission rate was 36.11-931.61 g NH₃ cow^-1day^-1 using N/A method and 147.68-1048.12 g NH₃ cow^-1day^-1 for N/P method. The results don’t agree well with the ammonia emission values in other published literatures.

The wind tunnel system has been developed with better aerodynamic characteristics. The air velocity profile, turbulent intensity and temperature profile indicate that relatively stable temperature, turbulent intensity and air velocity are observed at the position of 8.5 inch under the top of tunnel hence this position is the ideal position to measure air velocity and temperature before and after sampling section for this tunnel system. In the flux chamber testing, 99.73% and 0.27% of total nitrogen loss from dairy manure are in the form of NH₃ and N₂O respectively in the indoor temperature (21°C).