permaculture

[Toby Hemenway <hemenway@jeffnet.org>]

Title: Re: Wood shavings in compost

on 2/27/01 2:54 PM, Roger W. Greene Jr. at envirochef@acadia.net wrote:

> I have been composting horse manure mixed with straw and wood shavings (pine). Does anyone know the pros and cons of wood shavings in compost. I have noticed that it takes longer for it to break down.
> R
>
> I use a similar stable bedding in my compost and for sheetmulch. The wood, since it has a high C/N ratio (about 400-800 to 1) requires a lot more nitrogen than most other compost materials to become a balanced food for the microbes that create compost (20:1 or so is ideal). So you'll need to use more green or nitrogenous materials than if you composted with, say, straw (80:1) or leaves (50:1). Lots of grass clippings, urine, or kitchen scraps would help. Rock dust or greensand are also useful to provide the minerals that are lacking in wood.
>
> Wood is high in lignin, a highly crosslinked carbohydrate that is difficult for bacteria to break down--that's another reason why it composts so slowly. Fungi are the best organisms to break down lignins, so you could inoculate your pile with some soil from  woody forest debris (forest soils support high fungal populations, rather than bacterial). Elaine Ingham's site, http://www.soilfoodweb.com has more information on supporting fungal growth in compost.
>
> The only cons that come to mind offhand are that woody debris takes longer to break down (you know this; and it can be a plus in sandy soil) and it requires more minerals and N than other materials to balance all that carbon. One pro is that it makes great compost for orchards, which prefer more fungi in their soil (because of the woody litter).
>
> Toby