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ARS Home » Midwest Area » Bowling Green, Kentucky » Food Animal Environmental Systems Research » Research » Publications at this Location » Publication #324749

Title: Methane generation during swine manure windrows: a case study

item Lovanh, Nanh
item Loughrin, John
item Cook, Kimberly - Kim
item Silva, Philip - Phil
item Sistani, Karamat

Submitted to: Florida Section - Air and Waste Management Association Annual Conference
Publication Type: Proceedings
Publication Acceptance Date: 4/7/2016
Publication Date: 6/17/2016
Citation: Lovanh, N.C., Loughrin, J.H., Cook, K.L., Silva, P.J., Sistani, K.R. 2016. Methane generation during swine manure windrows: a case study. Florida Section - Air and Waste Management Association Annual Conference. 1121.

Interpretive Summary:

Technical Abstract: In the era of sustainability, utilization of livestock wastes as soil amendment to provide micronutrients for crops is very economical and sustainable. It is well understood that livestock wastes are comparable, if not better, nutrient sources for crops as chemical fertilizers. However, the large concentrated volumes of animal manure produced from livestock operations and the limited amount of available nearby agricultural land areas necessitated the need for volume reduction of these animal wastes. Composting of these animal manures is a viable option for biomass and pathogenic reduction in the environment. Nevertheless, composting also increases the potential generation of unwanted emission of anthropogenic air pollutants such as greenhouse gases (GHGs) and other compounds via volatilization. In this study, we examine the generation of methane (a greenhouse gas) from swine manure windrows to evaluate the benefit of biomass reduction in conjunction with the potential generation of GHG. The feedstock for the windrows was obtained from swine farm in Kentucky where swine manure was mixed with wood shaving as bedding material. Static flux chambers and depth gas sampler along with photoacoustic gas analyzer and gas chromatograph were used to monitor GHG concentrations during the composting process. The results show that methane flux was quite high during the initial composting process and after the turning of each compost pile. Methane concentrations were also quite high in the center of the compost piles as compared to the outer surfaces. Over the period of roughly three months of composting, the BOD decreased by about 90%. In addition, the overall trend indicated that methane production decreased as the composting process continued. Although composting of animal waste is quite beneficial for biomass reduction, composting may not be economically feasible from an agronomical point of view due to time, nutrient loss, and potential environmental pollution (greenhouse gas emissions). Therefore, additional studies are needed to assess and validate the economics and environmental impact of animal (swine) manure composting (e.g., crop yield or impact on climate change and the environment).