Subject: HOW TO BUILD/START A�����

From: [email-masked] (Jim Mcnelly)
Date: Thu, 30 Mar 1995 01:45:00 +0600

Allen replies regarding composting:

AA> There are as many ways to build bins as there are people who
AA> compost.  I use the heavy wire "hog panels" and steel fence posts to
AA> make three bins, about one cubic yard each.  It is important to make
AA> each of the bins large enough so that you have enough bio mass for
AA> all the stuff to heat up.  Too small a pile and it won't heat up
AA> properly.  

Hi Allen,

You are right in pointing out that open air bin designs should be near 
one cubic yard in size each. I have found that they can actually be a 
bit smaller, 36" x 36" x 30" which is around 3/4 cubic yard, or 21 cubic 
feet. Over 30" high is hard to load. Most residents, however, do not 
generate so much material, and they do fine with the smaller 10 cubic 
foot plastic bins. They work because they are enclosed and do not dry 
out on the sides and loose heat like open air designs do.

Your biggest problem will likely be handling grass
AA> clippings.  Too much grass and your pile will get VERY hot (which is
AA> good) but it will also start to generate ammonia (which is bad) and
AA> it will stink (which is also bad).  

It used to be that very hot temperatures were universally considered to 
be good, but research from the mushroom industry in Holland, which has 
been confirmed by studies at Rutgers University and dozens of commercial 
sites, show that temperatures above 147F pasteurize the compost mass and 
actually kill the very beneficial organisms which optimize the 
decomposition process. Modern commercial composting systems now try to 
keep temperatures under 140F.

Offset this by keeping lots of
AA> dried organic matter around to layer with your clippings. Tehnically
AA> you want a carbon to nitrogen ratio of about 10:1, but who measures
AA> such things?  

I and others in the commercial composting industry regularly measure 
such things, and I believe that the number you are looking for is 
actually 30-1. 10-1 carbon to nitrogen ratio is equivalent to raw fresh 
fish, spoiled grain, raw sewage and even concentrated chicken manure. 
All of these materials are prone to producing odors and should be mixed 
with a carbon rich material. Even grass clippings are only around 25-1, 
which is not that far off.

Turn your pile once a week, religiously.  

More and more composting operations are using air from the bottom of the 
pile and are reducing the turning process. The general theory is now to 
mix the pile thoroughly before composting, then mix *once* after a week. 
The subsequent mixing stages are of diminishing value if the pile is 
aerated from the base.

It (mixing) serves
AA> three purposes.  One, is that it moves what is on the outside of the
AA> pile, to the inside assuring even composting.  

This is exactly right and is the most important reason for mixing.  

The second is that is
AA> ensures an adequate flow of oxygen.  

This common misperception has been disproven by studying oxygen levels 
inside of compost piles. Studies show that a pile uses up the oxygen 
provided by turning in about 30 minutes. The key is to provide air from 
the base of the pile and let the compost oxygenate itself 24 hours a 
day, seven days a week. In large piles over 10 cubic yards, forced 
aeration with blowers is necessary.

The third is that the process
AA> of turning mechanically helps break bigger pieces into small ones
AA> which also speeds up the process.  

This is also true, although screening at the end of the process and 
recycling the oversize material into the next pile as bulking matter and 
inoculant is where the commercial industry is moving toward. I have 
found that people are intimidated by the effort and mess of turning 
piles, and welcome the suggestion to get air and a good initial mix to 
do the work instead of the back.

Personally, I enjoy turning piles, but then I am a fanatical composter, 
making a fresh batch every two weeks during lawn mowing season. I 
wouldn't think of using a mulching mower. Where else would I get all the 
material I need for making home brewed compost?

Mr Compost~~~

Jim~ McNelly
[email-masked]

 * RM 1.3 02460 * May you live in interesting times.

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From: [email-masked] (Jeff Cook)
Date: 31 Mar 1995 17:48:52 GMT

In article <[email-masked]> [email-masked] (Jim Mcnelly) writes:

>be good, but...temperatures above 147F pasteurize the compost mass and 

The high temperatures in a compost pile are supposed to destroy bad
bacteria and chemicals, making the compost safe to use on your garden.
I'm curious, how do these lower temperatures affect the safety of the
final product?  (If the good organisms are thriving, won't the bad ones
be thriving as well?)
--

Jeff Cook                                         [email-masked]