Composting is gaining rapid acceptance by the beef cattle industry. Before the value of this manure management option can be fully determined, a few questions need to be answered about greenhouse gas emissions that contribute to climate change, say researchers in AAFC's Environmental Health Program. The scientists are helping develop farm management practices to promote innovation for economic growth, maintain security of the food system, and protect overall health of the environment as part of Canada's Agricultural Policy Framework, a recently adopted government agriculture program.
In this study, project leader Xiying Hao and her colleagues Chi Chang and Frank Larney compared composted manure from cattle bedded with traditional straw or wood chips to determine the respective levels of greenhouse gas emissions. The work was conducted in the summer of 2001 at the AAFC Research Centre in Lethbridge, Alberta. Their findings, published in the January-February 2004 issue of the Journal of Environmental Quality, show that overall the emissions of greenhouse gases (carbon dioxide, methane and nitrous oxide) were quite similar for the two types of bedding during open windrow composting.
Recently, the lumber industry has been promoting the use of wood chips as an alternative bedding material to traditional cereal straw. Wood chip bedding is a mixture of bark, post peelings, and sawdust. Compared to straw bedding, wood chip bedding requires less frequent additions, keeps animals cleaner, and can be cheaper in drought years when straw is scarce. However, the effect of different bedding materials on greenhouse gas emissions during composting of manure had not been previously studied.