[USCC] Use of Composted Manure on Food Crops

[Tim Evans]

I think Dennis Avery is broadly correct - whatever his motive.  A
significant proportion [10%?] of cattle and sheep have symptomless infection
with E. coil O157:H7 and shed log8/gDS in their faeces irrespective of
whether they are fed on grass or corn - 'organic' or 'conventional'.  Any if
they have, why not deer and other wildlife.

We found O157 had a similar susceptibility to treatment methods (including
composting) as other strains of indigenous E. coil.  This is contrary to
some reports that measured against laboratory strains - apparently lab
strains are "flabby" and not as resilient as the guys out in the mean
streets of digestive tracts.  Fortunately not many people have O157 and
therefore it is not common in municipal sewage.
UKWIR (2000) Methods for detection of pathogens in biosolids.  Report ref.
00/SL/06/05.  UKWIR, London 
UKWIR (2002) Pathogens in biosolids the fate of pathogens in sewage
treatment.  Report ref. 02/SL/06/6.  ISBN: 1 84057 2612  UKWIR, London

Composting would kill O157 just like it kills other faecal coliforms, but as
Dr. Robert Tauxe is quoted as saying, you have to hit the time-temperature
relation in every part of the manure. I'm sceptical that many farms can
achieve this - how many have windrow turners to really shred and mix the
manure etc.? 

The Chilled Food Association here requires a long layoff between spreading
manure and planting crops that will be eaten raw.  It's not rocket science
is it?  Generally manure would not meet Class-B biosolids faecal coliforms
limits and we don't allow Class-B on salad etc. crops. 

There are also the questions of run-off from grazed fields where animals
drop their dung [some of it log8 O157], of irrigation water if it is taken
from surface waters and of wildlife - they crap too.

It is not a sterile environment out there!

regards

Tim

 
Dr Tim Evans
TIM EVANS ENVIRONMENT
Stonecroft, Park Lane, Ashtead, Surrey KT21 1EU England
tel/fax +44 (0) 1372 272 172 mobile +44 (0) 7816 833 991
tim at timevansenvironment.com


-----Original Message-----
From: McNelly, Patrick [mailto:PMCNELLY at OCSD.COM] 
Sent: 04 October 2006 17:36
To: US Composting Council Compost Discussion List
Subject: [USCC] Use of Composted Manure on Food Crops

The following article by Dennis Avery was picked up today in the Orange
County Register, and I'm sure that is has appeared elsewhere recently.
I'd be interested in the opinions of other members of this list on this
topic.  Avery has a long history of opposing using composted organics in
agriculture.  I can't vouch for the veracity of anything he says here,
but I suspect he hasn't gotten all of his facts straight.




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