What Farmer Educators Need to Know about Mortality Composting – Beyond the Basics Quality Assurance in Mortality Composting, Mortality Composting Safety

Composting is the aerobic, or oxygen requiring, decomposition of organic materials by microorganisms under controlled conditions. Microorganisms consume oxygen while feeding on organic matter and, as a result, give off heat and carbon dioxide. In conventional composting, operators manage the process variables, feedstocks, air, moisture and shelter, to optimize the slow natural decay process (i.e., when these elements are out of balance). Green, wet, nitrogenous feedstocks are mixed with brown, dry, carbonaceous material creat-ing a carbon to nitrogen (C:N) ratio in the range of 20 to 30:1 along with the proper amount of moisture. The windrows or piles are then managed via monitoring and turning for proper air-flow and temperature in order to speed up decomposition, eliminate odors, and destroy pathogens and weed seeds. Mortality composting does not follow the rules of starting with a “mix ” of the right moisture and C:N ratio. In mortality compost-ing, the diet is all wrong (C:N about 50:1), air flow occurs passively, and moisture comes from the carcass as it decomposes. Instead, an envelope of carbon material simply allows the natural process of decomposition to occur in a manner that will absorb the moisture and odors emitted when carcasses decay. Composting of mortalities started in the late 1980s when Dr. Dennis Murphy at the University of Mary-land designed a successful poultry composting facility using a series of bins. Other methods of composting dead birds, including windrows, were quickly adopted. Using these same principles, composting of large