[USCC] technical definitions of finished compost

[Craig Coker]

Cathy:

While I certainly agree with Frank's definition, I would also note that it
depends, to some extent, on the market for the product.  For example, a
North Carolina producer sells much of their compost to row crop agriculture
during fall and winter, where the compost is allowed to winter over prior to
spring plantings.  So, in that application, a fully mature compost is not
needed at the time of application, as it will mature in-situ, so to speak.

To answer your question as to what happens in the curing process, I define
it as a mesophilic composting stage designed primarily to oxidize volatile
fatty acids formed by the decomposition of fats, oils and proteins in the
primary composting stage.

However, as Frank wisely noted, opinions on the definition of curing are
like noses; everybody has one!

Best regards,
Craig
 
 
Craig Coker
Coker Composting & Consulting
3331 Glade Creek Blvd.  Ste. 7
Roanoke, VA  24012
(540) 904-2698  Fax: (540) 904-6732
Cell: (540) 874-5168
craigcoker at cox.net
www.cokercompost.com
 
 


-----Original Message-----
From: compost-bounces at mailman.cloudnet.com
[mailto:compost-bounces at mailman.cloudnet.com] On Behalf Of frank
Sent: Thursday, November 29, 2007 3:00 PM
To: Compost Discussion List
Subject: Re: [USCC] technical definitions of finished compost

Cathy,
I look at it this way: But there are many ways to look at it.

"Finished" is when compost is 'stable' and has 'cured'.

Stability  is when the available carbon  under ideal conditions (pH, 
nutrients, porosity, temperature etc)  are degrading (producing CO2 and 
using up O2 from the environment) at a rate low enough so the loss in 
oxygen during decomposition can be easily replenished in the environment 
(not go anaerobic) and the rate is slow enough so the changes in 
chemistry (available N, uptake of N etc) can be easily handled by the 
farmer.

Curing; Once a compost has stabilized there can be pockets of toxins 
remaining due to the speed the stabilization has occurred. Now that the 
oxygen demand has slowed there is more available to let the microbes 
convert ammonia to nitrates (example) etc.

Frank




Cathy Gill wrote:

>Hi all! 
>
>You've been so helpful in the past so I was wondering if you wouldn't mind
answering a couple of more questions for me.
>
>What is the technical definition of when compost is "finished"? does it
have to reach a certain temperature and then cool? Or is it based on levels
of microorganisms that are active? I am very interested in knowing the
science behind this.
>
>Also, I have read somewhere that, at least in a home setting, compost that
is finished may still need to be cured. How does one know when it is cured?
What happens during the curing process? 
>
>Thanks in advance!
>
>Cathy Gill
>
>AthenaES
>1450 S. Rolling Road
>Baltimore, MD 21227
>410-455-6319
>www.athenaes.com
>cathy at athenaes.com
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-- 
Frank Shields
Soil Control Lab
42 Hangar way
Watsonville, CA  95076
(831) 724-5422 tel
(831) 724-3188 fax
frank at compostlab.com
www.compostlab.com


Join us at the US Composting Council's 16th Annual Conference & Trade Show
Oakland Marriott City Center, Oakland, CA | February 9-12, 2008.
The National forum for those involved in the development and expansion of
the composting and organics recycling industry.
Conference Highlights, Registration forms, Exhibitor information and
Sponsorship Opportunities available at the USCC website:
www.compostingcouncil.org or call the USCC at 631.737.4931 
____________________________________________________________________________
__
Compost maillist - compost at mailman.cloudnet.com
http://mailman.cloudnet.com/mailman/listinfo/compost
_______________________________________
This list is a service provided by the US Composting Council (USCC).
(c) Copyright 2004 United States Composting Council - All rights reserved

Opinions expressed do not necessarily represent the USCC, the Foundation, or
the Board of Directors.

Non-members of USCC are encouraged to join the Council through its website
at: http://www.compostingcouncil.org/membership.cfm

Members posting CC copies to the list and other addresses may have their
posting privileges suspended. For discussion list policies and information
regarding subscribing, unsubscribing, digest or other options, go to:
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For additional help in unsubcribing or to report bugs and problems, send a
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