This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: Newspaper Mulch

Thanks, Richard for this exhastive response. I feel much better about usinf
newspaper now!

Denise McCann Beck
USDA Zone 7
Sunset Western 4
Coastal Bristish Columbia

----------
> From: Richard Grazzini <rickg@centrelab.com>
> To: veggie-list@eskimo.com
> Subject: Re: Newspaper Mulch
> Date: Thursday, May 08, 1997 3:37 PM
> 
> Denise, 
> On Sunday, May 04, 1997 12:36 AM
> you wrote:
> > Thinking so does not MAKE it so. I would simply like to point out that
> > there is a BIG difference between animals lying on paper products and
> those
> > same paper products with their attendant ink, coatings and
printer/copier
> > toners decomposing and being absorbed by the vegetables I eat! 
> 
> I should have foreseen that response.  Frankly, I have not seen any
recent
> literature regarding the migration of anything nasty from newsprint into
> plants grown in composted newsprint.  (And I would like to see it, if
it's
> out there.  I suspect the COMPOST list may have opinions here, but I do
not
> watch that one).  There used to be toxic organics in printer's ink a
decade
> or more ago: inks are now almost exclusively soy-oil based, not
> petroleum-derived.  The colors used to be toxic metal based (i.e.,
cadmium,
> chromium, lead) but not anymore.  The colors are now due to complex
organic
> molecules, just like the dyes that color clothing.  
> 
> Are these a problem?  Yes, it's possible.  But not after composting, or
> after decomposition in the soil.  The soil flora (fungi, bacteria) and
the
> flora in the gut of the soil decomposition fauna (worms, insects) that
> would chew on the paper would chew up those organic molecules and use
them
> for energy.  Seriously.  There's actually a sub-discipline in
environmental
> engineering called bioremediation, in which microflora are introduced
into
> a system in order to speed up the decomposition of organic pollutants in
> natural systems.  And it works.  
> 
> Consider a sewage treatment plant.  If the plant is working properly, and
> within design limits for capacity, the effluent water coming out of the
> plant is clean.  That's essentially bioremediation.  Similar degradation
> processes are going to occur in a compost heap, or in the soil in your
> garden, as long as you work to maintain a high level of organic matter in
> that soil.  
> 
> Why is OM important?  Worm food, for one.  Worms lead to aeration, and
the
> oxygen is good for the process.  Aeration encourages soil flora and
fauna,
> which can only help the breakdown process.
> 
> OM also binds things that could otherwise be a problem.  There are heavy
> metal-contaminated sites in the eastern US where the soil SHOULD be too
> toxic to support plants, but people safely garden in those areas.  How? 
By
> keeping the OM content high (the residents typically fertilize with lots
> and lots of cow manure).  The OM ties up the heavy metals, reducing the
> availability of the metals to the plants to a non-toxic level, and
keeping
> them in the soil.  And because the metals are tied up to the OM, they are
> NOT available to the plant, and do NOT get into the part you eat.  
> 
> The problem is that the OM needs to remain high in these areas.  If you
> quit adding OM, the OM content decreases (over a period of years), and
the
> heavy metal levels can become toxic to the plants. 
> 
> Rick Grazzini
> rickg@centrelab.com
> "It's ALL chemistry" -- Dr. R. O. Mumma
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index