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  • From: KAKerby AT aol.com
  • To: market-farming AT lists.ibiblio.org
  • Subject: Re: [Market-farming] manures/GAP training
  • Date: Tue, 2 Mar 2010 18:29:33 EST

I glossed over a lot of the detail from that class, because I wanted to keep the email short.  But to provide a few more details:
1) only mammalian or avian-based manures are a risk.  Earthworm castings are not a risk if they are dining on plant wastes.
 
2) There was a theory floating around for awhile that only intensively grain-fed ruminants could produce deadly variants of E coli, which would have been a nice reason (amongst many) to shut down feedlots.  But recent findings amongst wild elk in the Rockies indicates that grain-fed versus not-grain-fed doesn't matter.  Any warm-blooded creature (mammals or birds) can ingest, create and pass on E coli.  Grass-fed cows have also been found to carry deadly variants of E coli.  We use rabbits to build our beds here, and like you that seemed very reasonable to me until I learned that any mammal can produce those deadly strains. 
 
3) While using mulch and landscape fabric would be sufficient to protect the crops immediately above them, any contact you may have with the soil downstream of a contamination source is sufficient to cause contamination.  Any source of water-soil interaction (muddy spots in the driveway, disturbed soil while putting up fenceposts, etc) is sufficient to get it on your clothing and shoes which can then spread it around to the rest of your growing area.  It can be spread much like a cold can be spread from person to person - any form of direct contact.  But irrigation was listed as the #1 way that E coli can move around on the farm, and from one farm to another, because the water carries it along.  Contaminated irrigation water is the suspected source of contamination in several recent E coli contamination cases which made the news.
 
I'm not a huge fan of these new suggestions either.  I was just wondering what changes, if any, other growers might be making with these new research findings.  I remember during the last big flood here, farmers were told they couldn't market crops touched by the floodwaters.  The near-universal comment was "show me the research to back up your requirements and then I'll go along with it."  Well, now we've got some of those research findings.  Hence my question for what folks were going to do about it.
Kathryn Kerby
Frog Chorus Farm
Snohomish, WA
 
 
 
In a message dated 3/2/2010 2:58:49 P.M. Pacific Standard Time, gartht AT txcyber.com writes:
Greetings,

But not all manures are the same.  Using manure from grain eating cattle
can be deadly, I would not allow that on my property, period.   Our
cattle don't eat grain, but we would not use their manure anyway, it is
busy fertilizing the pastures, where it belongs.  We use rabbit and worm
castings, that is all.  The problem is that everything is being lumped
together, one size fits all.  210 days at rest would mean I could use my
garden beds every second year, since I don't have them empty that long,
I have a long growing season.  I do follow the 120 day rule, which for
rabbit manure seems perfectly reasonable.

My manure is under landscape fabric and mulch, no root crops grown in
those beds.  I basically don't grow root crops for sale.

I am glad I am direct sales to my customers and yes, they do know
exactly what I am doing.  They are very happy with it, and with my results.

Bright Blessings,
Kim

KAKerby AT aol.com wrote:
> The science behind the new guidelines were based on recent studies
> which have tracked how long E. coli lived either in the soil or on
> surfaces.  They provided details from one of the studies, which
> tracked soil, onion and carrot contamination, on four test plots per
> vegetable along with a control plot.  If you want the exact name and
> authors of the study, I can provide that but the title was pretty
> long.  Those results were published in the Food Microbiology journal
> in 2005.  In that study:
> 1) After the soils were innoculated, they then watched to see how long
> the populations would live in the soil, along with carrots and onions
> grown in the soil.  With the population numbers on a graph, the
> numbers stair-stepped down a few times throughout the experiment but
> quite a few were still alive at Day 120, with those final holdouts
> dying off between Day 180 and Day 205.  Furthermore, carrots and
> onions harvested from that soil continued to have viable E. coli
> survive on the surface of those roots for another long period -
> carrots harvested on day 126 still had viable E coli on them on Day 168.

> 2) Only 10 E. coli cells are sufficient to cause illness in human
> beings.  So having even extremely low counts still alive in the soil
> can provide for a 'bloom' later if the right conditions are met.

> 3) E coli is extremely mobile in irrigation water, which means that
> any soils containing E coli which are splashed or sprayed onto crops
> can carry the E. coli to any wetted surface.

> Someone asked whether the organic standards would be changed to
> reflect these findings.  The WSDA Organic Certification staffer
> replied "I sure hope so".  When the WSDA scientists were asked whether
> these policies were going to eventually move from being guidelines to
> being requirements, they replied that regulatory action may never
> occur.  But they also pointed out that large-scale buyers such as
> Walmart and Costco are already putting requirements like this into
> practice from the farmers and brokers they buy from.  Once those
> big-box buyers make decisions like that, the smaller grocers and other
> retailers quickly follow suit.  The WSDA staffers said once the bigger
> retailers all jump on that bandwagon, these guidelines economically
> become a requirement even if they are not yet a regulatory requirement.

> These are still "suggestions", to be sure.  And perhaps they always
> will be.  But the reasons for what they're recommending seemed pretty
> straightforward to me.  Having watched a few illness cycles bring down
> producers during past E. coli scares, I'd like to be able to look my
> customers in the eye and say 'yes, I am familiar with the risks and
> yes I take best management steps to minimize that risk.'  I've been
> asked that before and I'm not going to stop answering that question
> now.  If we didn't rely so heavily on animal manures and composts here
> to maintain soil fertility, I probably wouldn't be quite so
> interested.  But using those tools I felt the need to be respectful of
> when they can create problems.
> Kathryn Kerby
> Frog Chorus Farm
> Snohomish, WA
>
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