The organic residues with wider C : N ratios as compared to narrow C : N ratios are decomposed at

C : N ratio is the mass of carbon to the mass of nitrogen in organic residues.
The optimum ratio of C : N for the desired decomposition of organic crop residue is 24 : 1. It should be in proper carbon and nitrogen ratio that a microorganism can survive healthily in it.
The organic residues with wider C : N ratios as compared to narrow C : N ratios are decomposed at a slow rate.