North American Fruit Explorers mailing list at ibiblio

["robscott@freeshell.org" <robscott@freeshell.org>]

Charlie,

In preparing compost, people generally aim for a 20:1 carbon to nitrogen 
ratio to supply N to crops, and if you've got vegetable scraps in it 
you've probably got lots of other elements too (K, P, Ca, trace nutrients, 
etc.) Hardwood leaves can have high C:N ratio, e.g. 40:1 which will tie 
up N as the microbes use the abundant C and scavenge all the N, making the 
N unavailable to plants. Food scraps and manures tend to be on the low 
side, say 15:1, which means the N either mineralizes or is lost as N2 gas, 
but the N is plant-available and so the compost functions more like a 
fertilizer. The below webpage introduces the C:N balancing concept and 
gives a list of C:N ratios for common mulch and compost materials at 
the bottom.

Compost Fundamentals: Compost Needs - Carbon Nitrogen Relationships
http://whatcom.wsu.edu/ag/compost/fundamentals/needs_carbon_nitrogen.htm

I compost food waste (no meat), chicken manure, hay, and leaves at about 
1:1:1:1 ratio. My point is that the mixing ratio determines the results.

Rob Scott
Urbana Permaculture Project
zone 5 Urbana, IL