In categorizing organic residues as N sources for various farming systems, the use of initial residue chemical compositions quality indicators only is not adequate to guide their use in soil management.
Soil aeration is another factor that should be considered in the categorization, because it can bring about different N transformation patterns of a residue.
Other environmental factors, e.g., soil pH, texture and temperature, are also important for N mineralization.
They should be taken into account in future efforts to categorize organic residues.