ICAR-DMR sets nitrogen in the mixed raw materials at 1.5 to 1.75 percent of dry weight and the carbon to nitrogen ratio at 25 to 30 to 1, falling to about 16 to 1 after composting.
Both edges matter. Below 1.5 percent the heap may not pass 55 to 60 °C and moulds such as Stachybotrys move in. Above 1.75 percent, nitrogen leaves as ammonia and the compost is invariably infested by Sepedonium yellow moulds and ink caps. Nitrogen comes from whatever is cheap near you: ICAR-DMR gives wheat straw 0.6 percent, deep-litter chicken manure 3.0, wheat bran 2.0 and cotton seed meal 7.0.