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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #344029
Research Project: Improvement of Soil Management Practices and Manure Treatment/Handling Systems of the Southern Coastal Plain

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: A simple mathematical method to estimate ammonia emission from in-house windrowing of poultry litter

Author
item Ro, Kyoung
item Szogi, Ariel
item Moore, Philip

Submitted to: Journal of Environmental Science and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2018
Publication Date: 1/30/2018
Citation: Ro, K.S., Szogi, A.A., Moore Jr, P.A. 2018. A simple mathematical method to estimate ammonia emission from in-house windrowing of poultry litter. Journal of Environmental Science and Health, Part A. https://doi.org/10.1080/10934529.2018.1428273.

Interpretive Summary: In house windrowing between flocks is an emerging sanitary management practice to partially disinfect the built-up litter in broiler houses. Windrowing litter results in high litter temperatures that can reduce the risk of transmitting pathogens to next flock. Simultaneously, this practice may also increase ammonia (NH3) emission rates from the windrowing house due to higher volatilization rates associated with higher litter temperature. In this study, we developed mathematical models to determine the impact of windrowing litter on NH3 emission rates. Using these models, the heights of windrows yielding the smallest mass transfer area were estimated. These litter surface area predicting models were then integrated with published process-based mathematical models to predict the total house NH3 emission rates from windrowing house. The NH3 emission rate change calculated from the integrated model compared well with the observed values except for the very high NH3 emission rate from mechanically disturbing the litter immediately windrowing started.

Technical Abstract: In house windrowing between flocks is an emerging sanitary management practice to partially disinfect the built-up litter in broiler houses. Windrowing litter results in high litter temperatures that can reduce the risk of transmitting pathogens to next flock. Simultaneously, this practice may also increase ammonia (NH3) emission from the litter because NH3 in the litter volatilizes to the atmosphere more rapidly at higher litter temperature. However, windrowing litter also reduces the total surface area exposed to the atmosphere, thus reducing the house emission rate to certain extent. In this study, we developed mathematical models to determine mass transfer area of litter when the litter is windrowed to triangular- and rectangular-prismatic, and semi-cylindrical shapes. Using these models, the heights of windrows yielding the smallest mass transfer area were estimated. Smaller mass transfer area is preferred as it would reduce NH3 both emission rates and heat loss. The heights yielding the minimum mass transfer area were 0.8 and 0.5 m for triangular and rectangular prismatic windrows, respectively. Only one height (0.6 m) was theoretically possible for semi-cylindrical windrows because the base and the height were not independent. Above mass-transfer area predicting models were then integrated with published process-based mathematical models to predict the total house NH3 emission rates from the in-house windrowing of poultry litter. The NH3 emission rate change calculated from the integrated model compared well with the observed values except for the very high NH3 emission rate from mechanically disturbing the litter during the onset of in-house windrowing.