Market Farming

["David Guthrie" <dguthrie AT egyptian.net>]

Thanks Dave.  I think I confused the point with a spectrometer.

I thought I had understood ionic nutrients taken up by the plant produced
plant tissues that behaved in the same way and thus were more nutritious
being more absobable in animals and humans.  I thought this came from the
biodynamic school of ag.  Could have misunderstood though.

Thanks for your thoughts.  I'll continue to look into the subject.

David Guthrie
dguthrie AT egyptian.net



----- Original Message -----
From: <dave.kathy AT att.net>
To: "Dave Campbell" <dave.kathy AT att.net>; "Market Farming"
<market-farming AT lists.ibiblio.org>
Sent: Friday, August 22, 2003 9:12 PM
Subject: Re: [Market-farming] refractometers and soil penetrometers


> Hi, David!
>
> Well, you know light bends when it goes into and out of water.  If the
water
> has sugar in it, or other solutes, the light will bend even more.  So, I
> guess the refractometer just measures how much the light beam bent and
> translates that into equivalent sugar content.  It doesn't break the light
> into a spectrum, though.
>
> No, I definitely did NOT nean nutrient value has anything to do with ionic
> content; in fact, I was trying to say the opposite.  My point was that
> electrical conductivity depends (among other things, actually) on free
ions
> in the pore water, and that an ohm meter measurement will reflect them.
But
> I doubt that sugars and/or most nutrients fall into the category of free
> ions.  One respondent mentioned that ohm meters can be used on wet wood to
> check moisture in it, which I'm sure is true.  The resulting reading,
> however, will not tell the true electrical resistance of the wood.
However,
> it may give a relative index of moisture, at least if properly calibrated.
>
> Okay.  Hope that helps?
>
> Dave Campbell
> Tiffin Iowa
> > Refractometers deal with the light able to pass through the sample
broken
> > into the color spectrum?
> >
> > Nutrient value is dependent on ionic content?
> >
> > enlighten me (us) on the premise of the refractometer, if you would,
please.
> >
> > thanks.
> >
> > David Guthrie
> >
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