Effect of Different Intermediate Amendments on pH and Ammonia Emissions of Composted Poultry Mortalities10 January 2014
Composting with poultry litter may not be an appropriate best management practice if the aim is to minimise ammonia emissions during the disposal of dead birds, according to researchers in Canada.
The study of ammonia emissions from composting poultry mortalities has been a topic of interest due to concerns about air quality effects from agricultural facilities.
According to J.L. Spencer and B. Van Heyst of the University of Guelph in Canada, in previous poultry mortality composting research, it was reported that ammonia emissions are strongly affected by increasing the pH of the compost pile above 8.
To verify these findings, a project was initiated to examine composting poultry mortalities while using different amendments within the pile and observing the effects on the gaseous emissions.
Reporting their work in Journal of Applied Poultry Research, Spencer and Van Heyst explain that each pile was constructed using two layers of spent hen carcasses, with one layer below and one layer above the intermediate amendment. Each pile design was constructed in triplicate to assist in data verification and statistical analysis.
All piles were constructed using fresh woodchips for the base and cap material. The intermediate amendments were chosen based on their availability, applicability for mortality composting, and pH buffering.
The control pile had woodchips as the intermediate amendment, as it had a pH closest to neutral (7.4). The two additional pile designs consisted of intermediate amendment layers with either poultry compost, a lower pH material of 5.5, or poultry litter, a slightly higher pH material of 7.5.
Air samples were collected using a dynamic flux chamber drawing fresh air across the pile face at a known volumetric flow rate of approximately 370 cubic metres per hour.
Based on the results of this experiment, Spencer and Van Heyst concluded that using poultry litter for composting may not be an appropriate best management practice if the objective is to minimize ammonia emissions.
Spencer J.L. and B.J. Van Heyst. 2013. Effect of different intermediate amendments on pH and ammonia emissions of composted poultry mortalities. J. Appl. Poult. Res. 22(4):700-714. doi: 10.3382/japr.2012-00632
You can view the full report (fee payable) by clicking here.