Plant residues have a carbon to nitrogen ratio (C/N) of 50:1.

As long as the carbon to nitrogen ratio (C/N) in the soil is above 30:1, nitrogen will be in short supply and other bacteria will feed on the ammonium and incorporate its nitrogen into their cells.

Urinary losses were calculated from the energy to nitrogen ratio in urine.

This usually translates to having appropriate carbon to nitrogen ratios (C:N).

This is controlled with a higher carbon to nitrogen ratio, or increased aeration by ventilation, and use of a coarser grade of carbon material to allow better air circulation.

It needn't even be a chemical weapon, we could simply increase the nitrogen ratio until they black out.

Compared to E. fetida, E. hortensis does best in an environment with a higher carbon to nitrogen ratio.

A low silicate to nitrogen and phosphorus ratio allows coccolithophores to outcompete other phytoplankton species; however, when silicate to phosphorus to nitrogen ratios are high coccolithophores are outcompeted by diatoms.

The presence of toxic compounds combined with a low carbon : nitrogen ratio make the leaves and branches of scleromorphic species long-lived in the litter, and can lead to a large build-up of litter in woodlands.

Some mulches such as straw, peat and sawdust may negatively affect plant growth because of their wide carbon to nitrogen ratio, because bacteria and fungi remove nitrogen from the surrounding soil for growth.