Composting manure is much like composting organic food and yard scraps. The manure is piled and then periodically turned. In order to kill weed seeds and pathogens, all of the compost must be heated to 145 degrees Fahrenheit -- which only happens in the center of the pile. Periodically turning the pile helps ensure all of the manure is heated to this temperature and introduces oxygen to the material.
Composting manure before using it as a soil amendment is a growing trend as of 2011, according to the Colorado State University Extension. Composting the material first reduces the odors associated with it; it also reduces the manure's volume by up to six times because much of the water evaporates.
Composting manure systems are especially useful for those who garden in sandy soils. Sandy soil does not retain nutrients or moisture well, nor does it stick together in clumps. Manure, however, does all of these things. Composted manure can be applied at any time of the year in layers of 1 to 2 inches deep, and then tilled through the soil.