Composting has gained rapid acceptance as a method of recycling relatively dry organic materials such as leaves and brush and, when alternative disposal costs are high, even moist materials such as grass clippings and dewatered sewage sludges. However, as moisture contents rise above 60%, the need for a dry bulking amendment increases the costs of composting, both by direct purchases of amendment and though increased reactor capacity and materials handling requirements. High moisture mate-rials also present increased risks of anaerobic odor formation through reduced oxygen transport (Miller 1991). These costs and operational challenges often constrain the op-portunities to compost high moisture materials such as agricultural manures. During the last several decades economies of scale in livestock production have been increasing livestock densities and creating manure management …