Masters Theses

Date of Award


Degree Type


Degree Name

Master of Science


Biosystems Engineering Technology

Major Professor

Shawn A. Hawkins

Committee Members

Jennifer M. DeBruyn, Nourredine Abdoulmoumine, Forbes Walker


Poultry litter is a key factor that effects broiler (meat chicken) production because it can harbor pathogenic bacteria. Windrowing, which is akin to in-house composting can improve poultry litter quality and limit pathogen growth by heating and drying the litter between flocks. Generally, broiler producers manage windrowing to reach high peak temperatures as fast as possible, to reach efficiently pathogen control standards. Biochar, a carbon rich byproduct of biomass energy production, has the potential to improve windrow heating performance by facilitating higher peak temperature and heating rate. In this study, two sources of biochar as litter amendment prior to windrowing, Proton Power biochar and City of Lebanon biochar. Pathogen control standards were 122 °F for 24h or 145 °F for 1h, under these standards the pathogens in litter can be destroyed. For the farm scale part of this study, windrow heating performance was monitored in two paired commercial broiler houses, one that received 4000 lbs (1815 kg, dry weight, about 1% of litter in house) versus a control house that did not receive biochar. There was no significant difference in the peak temperatures attained during windrowing in the control and biochar amendment houses. For all treatments, the litter at middepth and floor positions of the windrow can reached ≥122 °F for 24h, in the Turn 1 and Turn 2; only the mid-depth position can reached ≥145 °F for 1h at mid-depth, in the Turn1 and Turn 2. The surface position had poor heating performance, did not reach either standards. In the second part of the study, a bench scale experiment was performed to evaluate the effectiveness of two biochars in simulative windrow heating at 1%, 5%, and 10% (dry mass based) amendment rates. In this experiment, the litter moisture was adjusted to 36% during the second simulative windrow turn. Compared to the non-biochar added control, the biochar again showed no improvement of heating performance. However, the added moisture significantly improved windrow heating in second simulative windrow turn. The bench scale study also illustrated that moisture is a key determinative factor in windrow heating performance.

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