Shelley Hawkins-Clark quoted a friend as follows <snip>
"One of the reasons that the pro-organic position doesn't hold up so well
scientifically is that a "molecule is a molecule". The organism processes
the
molecule in exactly the same fashion no matter what the source of the
molecule is (assuming that is in a place where the organism can take it
in and in a form that is processable by the organism)." <snip>
I was a chemist in what seems like a life time ago, so will take a stab
at responding. I'll address fertilizers first then pesticides.
FERTILIZERS:
Many--though probably not all--non-organic fertilizers are salts. That
makes it difficult to talk about "molecules" because the ions easily
separate from each other in a water solution. I'll use ammonium nitrate
as an example. The positive ion (ammonium, NH4) and the negative ion
(nitrate, NO3) are relatively stable in and of themselves, but in many
ways they react as if each were its own molecule. In this case, both
ions contain nitrogen (N). If I remember the numbers right, NH4NO3 is
35% N.
The NH4 has to be converted to NO3 before plants can use it (certain
microbes do it, but it takes a little time). It is possible I have this
point backwards but if I do, the argument will still fit if you reverse
them.
When all you have to do is apply the salt, NH4NO3, the temptation is to
give a plant LOADS of Nitrogen. The effect is rather like letting a
child have LOADS of ice cream and cake. The plants put on a flush of
growth (or the child puts on lots of pounds in fat) but neither is
necessarily healthy.
Now, consider an organic fertilizer. Most are lower in % N to start
with and--at least those generally in favor--are NOT in the form of
salts. The latest issue of Organic Gardening Magazine lists 3% N for
alfalfa, 12% N for blood meal, and 6% N for soybean meal. It is my
understanding that some manures (bird guano?) are about as high in
nitrogen as NH4NO3, but generally aren't considered acceptable in organic
production even though they are derived from life forms (the original
defination of the word, organic).
Let's take soybean meal as an example. You'd have to put almost six
pounds of soybean meal on a given patch to get as much nitrogen as you
would with one pound of NH4NO3. Even if you did put on six times as
much, the nitrogen in the soymeal almost certainly is not in the form of
either NH4 or NO3 until soil microbes have a chance to (slowly) convert
it chemically. The nitrogen in soymeal simply is NOT in the same
molecular form as in NH4NO3. The difference in the molecular form
represents a slowing down of the availability of the nitrogen in soymeal.
I suppose you could put too much nitrogen on with soymeal, but it is a
lot less likely than with most non-organic fertilizers.
Bottom line, the molecules are very different between non-organic and
organic fertilizers if you limit "organic" to those products accepted in
most organic certification programs.
Certainly, it is possible to put too much bird guano on, but I doubt if
any organic certifiers would allow much if any uncomposted bird
droppings. Meanwhile, I know of plenty of gardeners who have sad tales
to tell about burning their crops with chicken manure.
PESTICIDES:
Here it is easier to go back to the original defination of organic;
derived from life. I'll limit my discussion to chemical means of
controling a pest (as opposed to mechanical like fly swatters).
In an earlier post, I talked about milk being used to control powdery
mildew. Milk certainly is derived from life. Most (all?) non-organic
fungicides are derived from industrial processes. Is anyone seriously
prepared to say that both kinds contain the same kind of molecules?
Milk, like so many things in nature, is certainly complex, but I would be
very suprised if any its compounds are the same as the active ingredients
in any non-organic pesticide.
Here again, some pesticides pass the test of being derived from life
while being restricted or prohibited in organic production. I believe
nicotine is one of them.
The bottom line is that non-organic and organic pesticides simply ARE
NOT (with possible rare exceptions) the same molecules.
If your friend really ment to say "element" rather than "molecule" which
is the argument my county agent uses, it is valid to point out that
different molecules react differently even if they contain some of the
same elements. My county agent says nitrogen is nitrogen no matter what
its origin. I disagree. Even he admits NH4 and NO3 do not have the same
availability to plants.
If you assume exactly the same molecules, then the argument gets harder,
but identical molecules (and mixtures of molecules) is not the general
case in distinguishing organic from non-organic.
I hope I haven't added more confusion than I started with.
Best regards, Edna
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
To Unsubscribe: Email majordomo@cals.ncsu.edu with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
"unsubscribe sanet-mg-digest".
To Subscribe to Digest: Email majordomo@cals.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/san/htdocs/hypermail
This archive was generated by hypermail 2b29 : Mon Jul 03 2000 - 12:00:38 EDT