On Sat, 3 Apr 2004 18:47:58 +0100, Alan Gould
wrote:

Nick Maclaren writes

To clarify, you are referring to the 'composts' sold in garden
centres. The sort of thing that you get by composting household
organic waste is entirely different, and contains a lot of nutrients.

"Exact amounts of various minerals and substances in compost depend on
what went into the pile, how hot the pile became during composting,
and the extent of the composting process. Because of variations of
these conditions and inputs, compost does not have a consistent N-P-K
rating, although it should roughly equal 1-1-1." from:

http://www.mastercomposter.com/ref/faq.html#npk

"The NPK of Quoddy is 1.2-0.3-0.3 and Schoodic Blend is 0.6-0.3-0.3"

I assume these are local brands of compost available to readers of
this site:

http://coastofmaine.com/wwwboard/messages/131.html

"Compost N.P.K. 1.4-3.5 : 0.3-1 : 0.4-2 Well made compost that
contains a large number of ingredients from many different sources
will have adequate amounts of most essential major and trace elements.
Compost, combined with any animal manures produce the best and safest
all purpose fertiliser, containing both major and minor elements."
from:

http://tinyurl.com/37ez7 (a PDF document from an Australian source)


And here's a site that collects many references to N-P-K figures for
organic materials:

http://www.ecosyn.us/ecocity/Links/M..._manure01.html

Compost *does* contain nutrients -- I didn't say it didn't. But its
benefit isn't in the amount of what we generally call "fertilizer" as
in a nutrient boost for veg crops in particular.



Commercial composts contain varying amounts of nutrients according to
whether they are described as seed, potting, growing etc., also
according to their John Innes category if given.

I was addressing compost, not various potting soils, seed-starting
mixes, topsoil, etc. The nutrition content of composts, home-brew or
commercial, *will* vary according to composition, but in general, the
garden/kitchen waste sort is quite low in the N-P-K values usually
associated with "fertilizer."