On a short term basis, poultry manure can also increase the soil organic matter content. To obtain maximum nutritive value, incorporate manure into the soil immediately after spreading. First year nitrogen availability coefficients for different poultry manures are shown in Table 6. For optimum utilization, manure should be used to meet as much of the phosphorus and nitrogen needs of the crops as possible. Use commercial fertilizer to furnish other nutrients to the levels needed as indicated by soil tests.
Ammonia production begins upon adding manure to a warm, moist soil.
Maximum levels of ammonia occur during the first two weeks. Research shows that 30 to 60 percent of the total nitrogen comes available during the first six weeks, depending upon the nitrogen content of the manure and the form in which it is present. The ratio of carbon to nitrogen is also important. High carbon litters such as sawdust may materially retard nitrate accumulations. The remaining nitrogen will be released very slowly during the process of decom-position of the organic residues.