During a three-year Nebraska study as much as 40 percent of total beef feedlot manure nitrogen and 60 percent of total carbon was lost to the atmosphere during composting. Because of nitrogen, carbon, and potassium losses from manure during composting, it may be more desirable to apply the manure directly as a nutrient source unless there are concerns about improving manure characteristics, killing weed seeds and pathogens, or reducing odor problems. Ideal values for these factors are given in Table I . Homogeneous manure solids can be composted alone without mixing with bulk materials. Dry and fibrous materials, such as sawdust, leaves, finely chopped straw or peat moss, are good bulking agents for composting wet manure or organic residues.
Temperature is the most common indicator of how composting is progressing.
Elevated temperature is necessary to destroy pathogens and weed seeds in manure or other organic materials. Depending on the ambient temperature, a complete composting process may take two to six months. The water content of mature compost should be less than 50 percent and preferably in the range of 30 to 35 percent. N ratio should be less than 20. Table I. Recommended conditions for rapid composting.