[Compostteas] chroma

Dave Robison drobison at teleport.com
Mon Jul 15 13:07:07 EDT 2002

On the housekeeping, I vote to show the originating handle in the "From" 
line so that we can reply without bothering the whole list if we so desire.

Someone wrote:
>Chroma I understand.  What does BD stand for?

Biodynamic. There's a lot of overlap between this group and Allan's BD Now! 
email group.
The idea behind the BD chromas was different. Pfieffer was trying to 
demonstrate the "formative forces" of natural materials. If you do a chroma 
on a mixture of compounds, you might expect to see a blob with circular 
bands of colors as the materials wick at different speeds to the outer 
circumference. But Pfieffer observed something different, "live" organic 
materials showed dynamic patterns, it's not just a uniform merging of 
colors. For some examples see the last part of the "Intro to BD class" at 

Are BD chromas easy to do? Well, not exactly. There are reasons to use 
silver, in part because it develops the colors. And that means that the 
papers have to be prepared shortly before use and kept in the dark -- light 
develops the silver. Finally, the interpretation of the chromas is 
difficult. How exactly does one classify patterns as "dynamic" or not? I 
have done a bunch of these chromas but never been too clear on what they 
reveal. My attempts at soil and compost just show a brown blob of humic 
acids, not very interesting.  I haven't tried it on the tea.

Do you need noxious chemicals? Maybe not. Ag is not so poisonous but it is 
expensive, stains clothes, etc. It is a potent biocide so disposal can be a 
problem. NaOH is used to extract the compost into liquid form, I think you 
could do without that, the tea is already soluble. Other metal salts can be 
used as color developer reagents, Fe was mentioned, but even that adds to 
expense. Filter paper can be used but coffee paper would be fine for a 
test, I would use the white paper to better distinguish color seperations.

And one needs a clean space for the work. The chemicals (if used) have to 
be measured precisely (needs a good scale and volumetric measures), 
dissolved in distilled water (no problem, readily available), and the 
papers need to dry is a fairly dust-free place (not every working farm has 

So I don't think BD chromas are the way to go. Can you do just plain 
chromas as Elaine suggests? Give it a try. But what compounds do you expect 
to see separated on the paper? And how will you be able to tell a good 
mixture from poor, given that we are using tea to spread the biolife, not 
the chemical compounds? I don't have a batch of tea going at the moment, 
but would be interested to hear other's experiences.

Dave Robison

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