Re: [compost_tea] MICROBIOLOGY TESTING of COMPOST TEAS
----- Original Message -----
From: soilfoodweb_at_aol.com
To: compost_tea_at_yahoogroups.com
Sent: Wednesday, December 22, 2004 2:55 PM
Subject: Re: [compost_tea] MICROBIOLOGY TESTING of COMPOST TEAS
In a message dated 12/22/2004 2:26:30 P.M. Pacific Standard Time, ted.pet=
erson_at_tcsn.net writes:
Except that we do it. We test piles extensively, and there are no huma=
n pathogens detectable. We do this routinely. It is possible.
But, do we have to demand it of everyone? I did not say that it was nece=
ssary. But certainly it is safer if we aim for that standard, and if we do=
n't quite achieve it all the time, that's ok.
Well, e coli exist in nature. They are everywhere. There's just not enoug=
h of them to have harmful effects and they are in environments that are not=
favorable to them. Large compost piles or windrows on earth made with man=
ures or a bird flies by and leaves a gift on the pile or. . . there are an=
y number of possibilities. ND means, I think, less than .02%. That doesn'=
t mean they are not there but -- oh well, we have discussed this before. I=
f they are there, even in miniscule amounts, they can multiply if the condi=
tions are right. I found with biosolids, the outbreaks could be controlled=
with compost tea. I have taken biosolids and composted them so that they =
show ND for pathogens. However, even composted biosolids that test ND fo=
r pathogens show pathogen regrowth spikes if it rains or if the moisture co=
ntent gets up above the 55% range. So testing ND for pathogens may be grea=
t but there can be regrowth. There seem to be a lot of factors that can ch=
ange compost that seems great into compost that has harmful potential as fa=
r as pathogens are concerned.
So here is a test I would like to see you make.
Get your compst tested for pathogens. When you have reached ND and as the =
compost is maturing, get it really wet. Say 60% moisture or more. Let it =
sit for a day without turning then test for pathogens. If you keep it wet =
and even turn it once a week, I would be interested in if you get pathogen =
spikes. Now, these spikes may still be below EPA recommendations for PFRP =
but they are spikes which would make the ND test results valid for the test=
but not necessarily indicative for pathogen control under all circumstance=
s.
Anyway, I agree that zero would be the best course and ND certainly the goa=
l with zero being a remote possibility. I produce a lot of compost but I'm=
sure it's a drop in the bucket compared to the amounts and varieties you p=
roduce and I am always willing to learn where I have gone wrong.
Ted Peterson
SOE
Received on Wed Dec 22 2004 - 21:55:16 EST
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