RichD wrote:
The local grocery has a compost recycle bin,
for food scraps etc. Even the plates and utensils
go in there.

Paper plates presumably, but dumping plastic or metal utensils seems
very wasteful. I presume this is in the USA throw away culture.

I was wondering, what constitutes 'composting'?

Usually making a big enough heap so that it will get hot by fungal
and/or bacterial action to kill weed seeds and decompose whatever is put
into it into fibrous loam. Takes 6 months - maybe less in ideal conditions.

I mean, does it simply get dumped into a big grinder,
or is there some enzymatic chemistry involved?

No need to grind it. The worms will do that for you. A decent hot
compost pile will get up to 70C or more internally a few days after
being built and may require turning over two or three times before the
material is all fully rotted down. Size matters. Anaerobic or
excessively wet ones smell bad.

And who/how/where receives it? Is it really
superior to petrochemical fertilizer, or is it
guilty conscience liberal feelgoodism?

It is in effect a soil conditioner. Same sort of thing as leaf mould in
a forest. You would get similar stuff by letting it rot down in situ
only done more controllably. Most municipalities that do large scale
composting make it available to allotment holders or large scale
horticultural sites.

Petrochemical fertilisers are a lot more concentrated but are neither
better nor worse as far as the plant is concerned. The biggest
difference is that adding bulky compost to a heavy clay soil will vastly
improve drainage and long term fertility whereas chemicals will only get
you a quick a temporary fix (if that).

Regards,
Martin Brown
** Posted from http://www.teranews.com **