In article ,
Beecrofter wrote:

OK for starters there are many tables listing the various amounts
percentage -wise of common materials that would end up in a compost
pile. And also tables that list the ratio between their carbon and
nitrogen contents. All available on line and in many organic gardening
books.

For a fast compost pile you need a few things

1 A volume of at least 1 cu yd
(more would be better so you metric types can use a cubic meter)
2 An evenly moist pile like a wet but not dripping sponge
( moisten as you make the pile )
3 Shredded ,chopped or otherwise divided ingrediants to increase
their surface
area
4 Bacteria and Fungi (if you build it they will come)

5 Enough nitrogen for the bacteria and fungi to make the proteins
they need to be able to grow and reproduce.

Where the ratio of 30:1 comes from is 30 parts carbon to one part
nitrogen.
Which approximates 3 parts vegetable to one part animal.
This gives you plenty of nitrogen to make proteins so the bacteria can
multiply.
Too much nitrogen and you lose it to the atmosphere too little and
your pile never heats up.

The whole purpose behind having a pile heat up is to destroy weed
seeds and pathogens.

YOU DON'T HAVE TO MAKE A STEAMING HOT PILE TO RETURN ORGANIC MATERIALS
TO YOU SOIL
You could just turn it under, use it as mulch , spread it on the
fields , etc.

The above is all true.

Sawdust ...
It ties up enough nitrogen to make a pile of grass clippings rot
without stinking.

The above is not. Firstly, you can compost pure grass clippings
without making a smell, simply by keeping them aerated. Secondly,
even sawdust will stink if you keep it so wet it is anaerobic
(though it will not smell as badly as many things). You can test
both out at home - I have.

The claim that you need a fixed proportion of nitrogen for effective
composting is pseudo-scientific nonsense. There is absolutely NO
point in reducing the proportion below that in grass clippings, and
mixing sawdust with them improves their composting by aeration and
not by diluting the protein.

This might NOT be the case if you were composting a large quantity
of mature pulses, household waste containing a lot of meat or manure.
In that case, diluting the protein could well be a good idea.


Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email:
Tel.: +44 1223 334761 Fax: +44 1223 334679