From: de5@ORNL.GOV (Dave Sill)
Subject: Re: Returning nutrients to the soil
Organization: Oak Ridge National Lab, Oak Ridge, TN
Date: Tue, 17 Nov 1992 16:00:26 GMT

In article <1992Nov16.162448.18365@nstn.ns.ca>, dc_ags@ac.nsac.ns.ca (Don Christie) writes:
>Dave Sill wrote:
>>such an unexpected anti-nutrient/poison exists.  E.g., if you use a compost of
>>indigenous plant matter and apply a dust made from local rock, it's very
>>nearly impossible that you'd be causing a substantial negative impact. 
>
>Now why would that be?

Because you're mimicking the natural processes that created the local topsoil,
and if there were any major nasties in there, they'd have impacted the local
flora.

>compost, as I understand is `rotted' plant and animal
>material... it's normally an excellent source of organic content in soil,
>and an excellent source of nutrients..... but.... the `rotting' process is
>accomplished mostly by fungi.

Wrong.  It's accomplished mostly by bacteria.  But even if fungi live in the
compost, they're indigenous fungi that the local flora tolerate (proof by
existence).

>It is a fact that 90 percent of the things
>that make plants sick are fungi....

Oh yeah?  Got a reference?  Not that it is relevant to the point...I just doubt
it's a fact.

>since the manufacture of compost can involve any number of fungal and/or plant
>species, there is no guarantee that some won't be pathogenic. (I refer here to
>your statement that it is `nearly impossible' to have a negative impact... I
>am merely stating one circumstance under which a compost could have a negative
>effect) 

If you stick to local vegetation, you're mimicking the same process that been in
place for thousands of years.  It's extremely unlikely that you'd be able to
create significant quantities of substances that the natural process doesn't.

>Local rock, when ground up, would seem to be a reasonable soil amendment...
>until one considers what effect it will have on the soil pH and nutrient
>content. Sometimes the availability of a given element to plants depends on
>the relative abundances of other elements. Phosphorus is one case in point.
>Unless some testing and qualification are done in terms of which rocks and
>how much rock, then it is not at all `nearly impossible' to have a negative
>effect on the soil environment.

Again, the local soil is formed from the local rock and decomposed local
vegetation.  The effect on pH of adding local rock will be pretty close to the
effect of the natural breakdown of rock into soil.

Is it really that hard to follow?  The closer one mimicks the natural processes,
the more likely one is to be practicing sustainable techniques.  That doesn't
mean there's no other way to do sustainable ag, though.  Techies prefer to
determine exactly which nutrients are consumed and in what quantities then whup
up a soup containing these nutrients in the prescribed quantities.  That's fine,
as long as it's done right, and takes into account the health of soil, etc., but
it's very *hard*.

>Under most circumstances, I agree, compost and ground rock make good soil
>amendments... but I take exception to the phrase `it is nearly impossible to
>have a negative effect' simply on the basis of the fact that the additives
>meet with the approval of the speaker. 

It's got nothing to do with having my approval--it's the fact that they're proven
effective and sustainable.

-- 
Dave Sill (de5@ornl.gov)                 Computers should work the way beginners
Martin Marietta Energy Systems           expect them to, and one day they will.
Workstation Support                                                -- Ted Nelson
Newsgroups: alt.sustainable.agriculture