Environmental impacts of manure management based on life cycle assessment approach

Horse manure is often a cost for horse owners, and in most cases, it is underutilized when its status as biodegradable waste means that it could potentially be used in renewable energy production and serve as a source of nutrient recycling. The selection of treatment methods requires information on possible environmental impacts; however, much readily available information on this aspect remains lacking. Therefore, in this study, the environmental impacts of horse manure management chains utilizing either saw dust or peat as bedding material are investigated using life cycle assessment, and global warming potential (GWP), eutrophication potential (EP), and acidification potential (AP) serve as impact categories. Selected manure management chains include different composting processes, anaerobic digestion, and combustion. The results reveal that combustion is the most favorable option for saw dust manure for all the studied impact categories, whereas anaerobic digestion is the most favorable for GWP reduction, and combustion is the best option for EP and AP reduction for peat manure. However, it should be considered that the selection of bedding material and treatment options for horse manure is restricted by the availability of bedding material and treatment options and by stable size and location.