RE: [compost_tea] Compost Tea 'Data' from Yale

From: Pawlett, Mark <m.pawlett_at_cranfield.ac.uk>
Date: Tue, 15 Feb 2011 11:30:23 +0000

Hi All

Just to make this clear. I can't see any evidence that this was actually p=
ublished. Published scientific papers are all subject to peer review exami=
nation by fellow scientists in the field. This appears to be a student res=
earch project report. Nothing more and nothing less. For an undergrad or =
MSc research project this report is fit for this purpose. Only the very to=
p students at either undergraduate or MSc level produce work of sufficient =
quality to publish in a scientific journal.

You are quite correct in some of your statements, there are some flaws in t=
he experiment. The compost tea, soil and compost are inadequately describ=
ed. Replication is unclear, and there are some problems with the statistic=
al design. The results and conclusion sections could be clearer. This pro=
ject is not perfect by a long shot, however I certainly would NOT describe =
this as shocking.

Student projects have limited time and money. As such they cannot cover al=
l analysis (e.g. nematodes). In order to gain both it is necessary to have=
 some form of financial investment from the users. I personally (as a Rese=
arch Fellow of Soil Microbial Ecology) have had an interest in compost teas=
 research for some time. Despite numerous attempts to find funds for compo=
st tea research from the users and research councils, I have had very littl=
e in terms of financial assistance for research into compost teas. Of cour=
se if anyone has any suggestions as to where I can find funds then I will c=
ertainly follow it up. It is my intention to supervise a PhD student resea=
rch programme on compost teas. Such a programme would allow a student to r=
esearch compost teas for 3 years, but of course financial investment is req=
uired to have scientifically robust data that can withstand the peer review=
 process necessary for scientific papers.

I would also like to stress that the methods used were also suitable. Inde=
ed microscopy would NOT be a suitable method for such work. Catabolic prof=
iles are a very important and valid way of describing the functional compon=
ent of the soil microbial community. There are numerous per reviewed paper=
s that are available that demonstrate this. Microscopy has inherent flaws =
in terms of bias.

The methods DO NOT only give data on bacteria. The data does not different=
iate between bacteria and fungi, but rather gives a functional profile of t=
he soil microbial community as a whole. Thus data includes both bacteria a=
nd fungi. A more detailed study would allow the research to use the method=
s to differentiate between fungi and bacteria. But the substrates used in =
the method are suitable, would be utilised fungal community, and have been =
published in peer reviewed scientific journals.

I wonder whether the un-named writer of the below had the courtesy to send =
his questions to the authors of the work to give them a chance to respond b=
efore sending into the group.

Dr Mark Pawlett
Research Fellow of Soil Microbial Ecology at Cranfield University.




From: compost_tea_at_yahoogroups.com [mailto:compost_tea_at_yahoogroups.com] On B=
ehalf Of Peter
Sent: 15 February 2011 00:22
To: compost_tea_at_yahoogroups.com
Subject: [compost_tea] Compost Tea 'Data' from Yale



Hi folks;

I just came across a published paper entitled "Closing the Loop: Alternativ=
e Land Management at Yale". The paper's root is located at http://environm=
ent.yale.edu/hixon/student-research/student-research-interns/

The paper is located here; http://environment.yale.edu/hixon/files/pdf/2010=
_Emily_Stevenson.pdf

Does anyone else find this paper a bit shocking? Here's another case of fla=
wed methodology and misunderstanding on how biological systems perform in t=
he real world.

There seems to be a complete disconnect on how compost tea is made.

 * Too many foods (certainly an anerobic tea they're referencing here)
 * No testing of compost tea
 * No mention of brewer design aside from a 'bubbler'
 * No DO data

No testing on their 'food waste' compost.

No mention of microscopy...at all.

Flawed methodology in before/after soil testing. Only bacteria are measured=
 using narrow range of foods. Where's the data on fungi, nematodes and prot=
s??

There's a misunderstanding of organic matter accumulation in soils. Can we =
expect appreciable increase in OM using 1,500 grams of compost, making tea,=
 diluting 1:1 and applying multiple times in a 6 X 6 meter area?

There's a major disconnect as to how to apply CT on a large scale and even =
the basics of equipment involved. It reads as though they're quite resistan=
t to changing there current chemical system.

I see lots of logarythmic scatter gram but not much in the way of science.

I'd expect to see somthing more substantial. This is a dissapointment from=
 an institution as fine as Yale.





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Received on Tue Feb 15 2011 - 13:07:12 EST

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