>Table 1. Average changes in the mineral content of some fruits and
>vegetables*, 1963-1992 [Bergner]
>
>Mineral Average % Change
>
>Calcium -29.82
>Iron -32.00
>Magnesium -21.08
>Phosphorus -11.09
>Potassium -6.48
>
>* Fruits and vegetables measured: oranges, apples, bananas,
>carrots, potatoes, corn, tomatoes, celery, romaine lettuce, broccoli,
>iceberg lettuce, collard greens, and chard
Given these declines. Given organic vs. conventional studies from the
late '80s that were (at best) inconclusive. Given the high dedication
to organic production principles at the time (ie, money was not the
motive as it so often is these days) ... the organic
movement/community/industry should go into a corner and hide from
embarassment.
Conventional agriculture has been producing food of persistently
deteriorating mineral quality. For all its philosophy and self
congratulation and boosterism the organic alternative is no better. If
organic farmers in the late '80s had simply been doing as well as their
conventional colleagues a quarter century earlier, they would have
'won' those comparisons with conventional in a walk-away.
Returning to my comment of yesterday, I'd also remind the reader that
--- in the field --- the mineral nutrient management situation on
organic farms is significantly worse that it was a decade ago. Leaving
aside the handful of superb organic farmers (the Richard deWildes and
the Ed Rezniceks of this business) what we have collectively
accomplished with minerals in the last twenty years of organics is,
precisely, nothing.
We would only have had to stay in place for twenty years to be coming
out far ahead in comparisons with conventional. That we have not
indicates with distressing clarity that the organic industry is all
sizzle and no steak when it comes to minerals.
>As an aside, this is what Dr. William Albrecht emphasized in his work
>as a soil scientist at the University of Missouri; i.e., animal
>feeding trials to ascertain the true quality of feedstuffs, writing:
>
>"cows are capable chemists"
>
>"as a chemist by experience and survival, not by academic training,
>the cow led the nomad over fertile soils"
>
>"we need to start observing and judging the cow as she is a chemist
>on the hoof guiding her own nutrition"
Particularly true in the case of calcium levels in forage, and in
particular of K:Ca ratios in alfalfa. Most alfalfa (conventional and
organic) has about 1% Ca. It ideally should be 2%. Potash is much
higher because potash is cheap and extension is continually encouraging
farmers to pour the potash onto alfalfa. Ideal potash in alfalfa is
about 2 - 2.5%.
If it's above 3%, you'll be seeing the vet more than you like.
If it's above 4%, you'll be seeing the knackerman (renderer) more than
you like.
If it's above 5%, you be seeing the *banker* more than you like.
Given the alarming declines of magnesium in human nutrition over the
last couple of generations. Given that it is usually a heart seizure
that kills cattle in low-magnesium grass tetany. Given the frequency of
human deaths from "apparent heart attack" (after which the autopsy
shows nothing) ... does anyone besides me see a connection?
>Other findings:
>
>*Lower nitrates in organically produced or fertilised vegetables.
I have to disagree with this one. Nitrate levels in vegetables are very
strongly correlated with *light* levels, which is why we routinely
refused to sell any lettuce (a nitrate accumulator) after the equinox.
Blood meal, and chilean nitrate have consistently produced higher
levels of nitrates in most crops than most conventional nitrogen
fertilisers. Manures were just as bad. Readers interested in more info
should contact ATTRA (800-346-9140) for a copy of the long, heavily
referenced work on nitrates that I did for them back in 1992.
Believe me, I don't buy California "organic" lettuce (fertilised with
chicken manure and/or Chilean nitrate) in the winter (cloudy, short
days).
>*Lower pesticide residues in organic fruit and vegetables
Generally true, by about an order of magnitude, if I remember
correctly. That is, about 25% of conventional produce shows some
residues, while only about 3-5% of organic produce does. Most pesticide
residues on conventional produce are below US government tolerance
levels (about 80% of those tests showing any residues at all, but I'm
going from memory here, so discount the number accordingly). Organic
exceeds tolerance levels only very rarely.
>*Higher dry matter content in organic products
Generally true, because nitrogen fertilizer tends to bulk up fruit and
vegetable yields with *water.* Total dry matter yield in a well-managed
organic produce operation can surpass that in a heavy-nitrogen
conventional system. This can account for the flavour advantage
sometimes accruing to organic.
Let's remember, though, that sugar metabolism is largely controlled by
calcium and mediated by boron, with magnesium and potash in supporting
roles. I have been able to increase sugar content of various crops by
20 - 50% simply by proper management of the forms and amounts of
calcium available to the plant.
If the organic produce farmer (having eschewed conventional nitrogen
and its organic cousins, like Chilean) does not also militate in favour
of high sugars, the result is very often disappointing yields of a
disappointing (to the consumer) produce.
Long-story-short: this mineral nutrient stuff matters a whole bunch for
both the quality and the nutritive value of foods and feeds. That the
overwhelming majority of organic farmers don't 'get' this any better
than their conventional colleagues is a continuing tragedy approaching
the point of having completely squandered a remarkable opportunity.
Bart
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