C/N of Compostable Materials

+/-6:1 +/-12:1 +/-25:1 +/-50:1 +/-100:1
Bone Meal Vegetables Summer grass cornstalks (dry) Sawdust
Meat scraps Garden weeds Seaweed Straw (grain) Paper
Fish waste Alfalfa hay Legume hulls Hay (low quality) Tree bark
Rabbit manure Horse manure Fruit waste Bagasse
Chicken manure Sewage sludge Hay (top quality) Grain chaff
Pig manure Silage Corn cobs
Seed meal Cow manure Cotton mill
waste

The lists in this table of carbon/nitrogen ratios are broken out as
general ranges of C/N. It has long been an unintelligent practice of
garden-level books to state "precise" C/N ratios for materials. One
substance will be "23:1" while another will be "25:1." Such
pseudoscience is not only inaccurate but it leads readers into
similar misunderstandings about other such lists, like nitrogen
contents, or composition breakdowns of organic manures, or other
organic soil amendments. Especially misleading are those tables in
the back of many health and nutrition books spelling out the "exact"
nutrient contents of foods. There is an old saying about this:
'There are lies, then there are damned lies, and then, there are
statistics. The worse lies of all can be statistics.'

The composition of plant materials is very dependent on the level
and nature of the soil fertility that produced them. The nutrition
present in two plants of the same species, even in two samples of
the exact same variety of vegetable raised from the same packet of