The fluxes of nitrogen are directly related to the carbon flows. When carbon is taken up into the microbial pool there is an associated nitrogen flow, NLitter1 and 2→Microbes, NFaeces→Microbes and NHumus→Microbes. Also when carbon is transferred to the humus pool there are associated nitrogen fluxes, NLitter1 and 2→Humus and NFaeces→Humus. All these nitrogen fluxes are calculated in the same way: by dividing the carbon flux by the CN ratio of the source.