In message , Franz Heymann
writes

"Martin Brown" wrote in message
...
In message , Franz Heymann
writes

My point was that I do not understand what process can determine
the
amount of arbitrary organic matter in a sample by simply shaking a
suspension of the sample in a liquid and looking for a colour
change.

Probably something like: a fairly powerful oxidising agent, a
catalyst
and a suitable indicator.

I am sincerely doubtful whether *all* organic compounds would respond
identically to such a group of agents.

Oh. I can assure you that *all* organic compounds will respond the same
way to sufficiently powerful oxidising agents - ending up as CO2. The
problem is that most of these chemicals are far too dangerous to be used
in a soil test. PTFE and a few other designer molecules might resist
attack at room temperature but ultimately even they give up the ghost.

It may be more specific than that - targeting
the acidic peaty component that is guaranteed to rot and change
volume.

That would be a pH meter. That does not measure "total organic
content", and would give wildly misleading results in limestone
country.

There are more cunning ways to measure humic acids.

I still think it is a scam.

I am pretty sure the test being sold is supremely irrelevant to
gardening, but if the Organic(TM) suckers want to buy into a spurious
chemical test of "goodness" then so be it.....

Regards,
--
Martin Brown

In article , Martin Brown
writes
I am pretty sure the test being sold is supremely irrelevant to
gardening, but if the Organic(TM) suckers want to buy into a spurious
chemical test of "goodness" then so be it.....

Well yes, but what is 'goodness'?
--
Alan & Joan Gould - North Lincs.

"Alan Gould" wrote in message
...
In article , Martin Brown
writes
I am pretty sure the test being sold is supremely irrelevant to
gardening, but if the Organic(TM) suckers want to buy into a
spurious
chemical test of "goodness" then so be it.....

Well yes, but what is 'goodness'?

That is what we have been trying to establish in this thread.

Franz

In message , Alan Gould
writes
In article , Martin Brown
writes
I am pretty sure the test being sold is supremely irrelevant to
gardening, but if the Organic(TM) suckers want to buy into a spurious
chemical test of "goodness" then so be it.....

Well yes, but what is 'goodness'?

According to Organic(TM) scheme it is mainly about getting premium
prices off the worried well for vastly overpriced and overpackaged
Organic(TM) branded goods in supermarkets. After being sanctified by the
acolytes of the Soil Association you can charge a massive premium.

Often the Organic(TM) stuff is flown half way round the world using
vastly more petrochemicals than it would require to grow it locally.

I have no problem at all with minimum inputs agriculture (as opposed to
modern intensive commercial farming) or local farmers markets, but
Organic(TM) is founded primarily on marketing concerns rather than on
real science.

Regards,
--
Martin Brown

In article , Martin Brown
writes
Well yes, but what is 'goodness'?

According to Organic(TM) scheme it is mainly about getting premium
prices off the worried well for vastly overpriced and overpackaged
Organic(TM) branded goods in supermarkets. After being sanctified by the
acolytes of the Soil Association you can charge a massive premium.

Often the Organic(TM) stuff is flown half way round the world using
vastly more petrochemicals than it would require to grow it locally.

I have no problem at all with minimum inputs agriculture (as opposed to
modern intensive commercial farming) or local farmers markets, but
Organic(TM) is founded primarily on marketing concerns rather than on
real science.

Well yes, but you still haven't defined 'goodness' in this context.
--
Alan & Joan Gould - North Lincs.

In message , Alan Gould
writes
In article , Martin Brown
writes
Well yes, but what is 'goodness'?

According to Organic(TM) scheme it is mainly about getting premium
prices off the worried well for vastly overpriced and overpackaged
Organic(TM) branded goods in supermarkets. After being sanctified by the
acolytes of the Soil Association you can charge a massive premium.

Often the Organic(TM) stuff is flown half way round the world using
vastly more petrochemicals than it would require to grow it locally.

I have no problem at all with minimum inputs agriculture (as opposed to
modern intensive commercial farming) or local farmers markets, but
Organic(TM) is founded primarily on marketing concerns rather than on
real science.

Well yes, but you still haven't defined 'goodness' in this context.

Convincing the punters to pay up willingly for overpriced goods.

Regards,
--
Martin Brown

In article , Martin Brown
writes
Well yes, but you still haven't defined 'goodness' in this context.

Convincing the punters to pay up willingly for overpriced goods.

There's a lot of that about, but I hadn't realised it was goodness.
--
Alan & Joan Gould - North Lincs.

"Martin Brown" wrote in message
...
In message , Franz Heymann
writes

"Martin Brown" wrote in message
...
In message , Franz Heymann
writes

My point was that I do not understand what process can determine
the
amount of arbitrary organic matter in a sample by simply shaking
a
suspension of the sample in a liquid and looking for a colour
change.

Probably something like: a fairly powerful oxidising agent, a
catalyst
and a suitable indicator.

I am sincerely doubtful whether *all* organic compounds would
respond
identically to such a group of agents.

Oh. I can assure you that *all* organic compounds will respond the
same
way to sufficiently powerful oxidising agents - ending up as CO2.
The
problem is that most of these chemicals are far too dangerous to be
used
in a soil test. PTFE and a few other designer molecules might
resist
attack at room temperature but ultimately even they give up the
ghost.

I was talking about responding by imparting a characteristic colour to
a test fluid.

It may be more specific than that - targeting
the acidic peaty component that is guaranteed to rot and change
volume.

That would be a pH meter. That does not measure "total organic
content", and would give wildly misleading results in limestone
country.

There are more cunning ways to measure humic acids.

I don't doubt that. By the way, I don't like the catch-all term
"humic acids".

I still think it is a scam.

I am pretty sure the test being sold is supremely irrelevant to
gardening, but if the Organic(TM) suckers want to buy into a
spurious
chemical test of "goodness" then so be it.....

Agreed

Franz

"Franz Heymann" wrote in message ...
"Martin Brown" wrote in message
...
[...]
There are more cunning ways to measure humic acids.

I don't doubt that. By the way, I don't like the catch-all term
"humic acids".

Well, now that we've disposed of the undoubted scam, in particular
applications catch-all terms may have their uses. For example, the
concentration of acidic humic compounds in a water sample is of
serious and proper interest, and most of the time no more specific
term is needed -- in fact, listing the compounds out would often be a
waste of space. I've just looked for another example, and at once
found an on-line oil-industry glossary which suggests that, at least
for one phase of that industry, the term's good enough for practical
purposes:

quote/humic acid

1. n. [Drilling Fluids] ID: 1986

Organic carboxylic acids of complex molecular structure (aromatic and
phenolic) that comprise 10 to 90% of lignite. Humic acids in lignite
react with caustic ingredients (NaOH and KOH) in mud. The water
solubility of lignite depends on its humic acid content.
Decarboxylation of humic acid groups by hydrolysis in alkaline muds is
a major source of carbonate and bicarbonate anions in water muds.
/endquote

You could afford to forget more about this than I shall ever have
known, but it seems to me that even such ordinarily useful expressions
as "fatty acids" or "amino-acids" could also be called "catch-all
terms".

(Deep breath.)

Mike.

"Mike Lyle" wrote in message
om...
"Franz Heymann" wrote in message
...
"Martin Brown" wrote in message
...
[...]
There are more cunning ways to measure humic acids.

I don't doubt that. By the way, I don't like the catch-all term
"humic acids".

Well, now that we've disposed of the undoubted scam, in particular
applications catch-all terms may have their uses. For example, the
concentration of acidic humic compounds

Yes, but what are "humic compounds"?

in a water sample is of
serious and proper interest, and most of the time no more specific
term is needed -- in fact, listing the compounds out would often be
a
waste of space. I've just looked for another example, and at once
found an on-line oil-industry glossary which suggests that, at least
for one phase of that industry, the term's good enough for practical
purposes:

quote/humic acid

1. n. [Drilling Fluids] ID: 1986

Organic carboxylic acids of complex molecular structure (aromatic
and
phenolic) that comprise 10 to 90% of lignite.

At least there we have an attempt at a definition, even if the
definition is a catch-all sentence.

Humic acids in lignite
react with caustic ingredients (NaOH and KOH) in mud. The water
solubility of lignite depends on its humic acid content.
Decarboxylation of humic acid groups by hydrolysis in alkaline muds
is
a major source of carbonate and bicarbonate anions in water muds.
/endquote

You could afford to forget more about this than I shall ever have
known, but it seems to me that even such ordinarily useful
expressions
as "fatty acids" or "amino-acids" could also be called "catch-all
terms".

Yes, I think you are right. {:-))

May we bring this diversion to an end by saying that humic acid is the
variety of acids which give peat a low pH?

(Deep breath.)

Even deeper breath,

Franz

In message , Franz Heymann
writes

"Mike Lyle" wrote in message
. com...
"Franz Heymann" wrote in message
...
"Martin Brown" wrote in message
...
[...]
There are more cunning ways to measure humic acids.

I don't doubt that. By the way, I don't like the catch-all term
"humic acids".

Well, now that we've disposed of the undoubted scam, in particular
applications catch-all terms may have their uses. For example, the
concentration of acidic humic compounds

Yes, but what are "humic compounds"?

I can't tell here if you are being serious or have a genuine
misunderstanding. It is in fact quite useful to categorise chemicals by
their generic properties rather than give very long names for each and
every compound in a naturally occurring and usually highly complex
mixture. Not least because of all the specific stereo chemistry of
natural materials.

quote/humic acid

1. n. [Drilling Fluids] ID: 1986

Organic carboxylic acids of complex molecular structure (aromatic
and
phenolic) that comprise 10 to 90% of lignite.

At least there we have an attempt at a definition, even if the
definition is a catch-all sentence.

The definition is simple enough. They are the acids that you get when
plant material like humus decays in peat and lignite. You can smell some
of their short chained aliphatic relatives in grass fermenting on the
compost heap.

Regards,
--
Martin Brown

"Martin Brown" wrote in message
...

[snip]

The definition is simple enough. They are the acids that you get
when
plant material like humus decays in peat and lignite. You can smell
some
of their short chained aliphatic relatives in grass fermenting on
the
compost heap.

I am rather disappointed that you snipped context from my previous
note without saying that you did so.

Franz