From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: Re: Oganic Foods "Non-essential"???
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Sat, 19 Dec 1992 07:41:02 GMT

Ted Altar writes:

>>Also non-essential would be the possibly greater nutritional
>>value of truly organically grown foods which one can always make
>>up for by eating a greater quantity of foods with a poorer
>>nutritional value.

George Clark exclaims:
>What? I can't believe you read this somewhere. You must have made
>it up. What even makes you think organic produce is more nutritional?

      Believe it or not, but there is some proper evidence for
this statement that I can cite.  Heck, you should know me better ;-)

     While maybe the effect is small in comparison to such things
as nutrient differences between plant species and even within
variations or breeds of a plant, there is empirical evidence that
organic foods can be richer in nutrients than conventionally
produced foods.  Again, I think other reasons for choosing
organic produce are more important, but permit me nevertheless to
cite some evidence in support of this conclusion about the better
nutrient quality of organically grown foods.

     Various studies (see below) have shown increased nitrogen
fertilizer use results in not only higher nitrate levels, but
also higher levels of free amino acids, oxalates and other
undesirable compounds, as well as, lower levels of vitamin C in
particular.  Calcium, phosphorous, magnesium and sodium content
are also affected by levels of chemical fertilizer use, as are
trace elements.

     Alternatively, there is evidence that organic fertilizers
and proper soil management practices will produce a more balanced
range of nutrients being available to the plant, than is the case
when readily soluble NPK mineral fertilizer is applied and taken
up by crops.  Comparisons of organically and conventionally
produced foods have in many cases (not all by any means)
confirmed these differences, but of course where soils are
already or still supplied with nutrients, the differences will
tend to be less marked.  Consider the results of the following 12
year study:

     Relative yield and composition of vegetables grown with
     composted manures compared with mineral fertilisers; result
     of a 12 year experiment.

     Yield:  24% lower
     
     Desirable components
          23% higher dry matter
          18% more protein
          28% more vitamin C
          19% more total sugar
          13% more methionine (important amino acid)
          77% more iron
          18% more potassium
          10% more calcium
          13% more phosphorous
     
     Undesirable components:
          12% less sodium
          93% less nitrate
          42% less free amino acids
     
     from Schuphan (1975).  "Yield Maximisation Versus Biological
          Value"  QUAL. PLANT, 24: 281-310.
                                

     We should note that while it is true that yields from
organic farming methods will be lower, this is not always the
case, especially as the soils are rebuilt.  Also, the savings in
fertilizer can often compensate for any lower yields.

     Now, just for the record, I'm not in principle against
chemical fertilizers but I do think that organic fertilizers have
a important role in proper soil care.  For example, A.G. Norman
of the University of Michigan almost 30 years ago noted that:

     "High yields are not . . . synonymous with a high content of
     nutrient elements. . . crops from well fertilized plots may
     have a lower content of some essential elements than those
     from poorly yielding plots, the addition of a fertilizer may
     cause a reduction in content of some of the other nutrient
     elements, or, if the supply of the major elements is such
     that the content of each in the plant falls in the poverty
     adjustment zone [where a partial deficiency of nutrients
     exists], moderate addition of one of them may have rather
     little effect on content."
          (from "Influence of environmental factors on plant
          composition"  THE NUTRITION OF PLANTS, ANIMALS, AND
          MAN, 1956., P.2)

     The majority of commercial fertilizers in use today are
relatively simple chemical preparations in comparison to the more
complex, bulky, slow-acting materials from organic matter.  "The
agronomist and the farmer are ordinarily preoccupied with yield"
Norman writes, "they are rarely concerned with mineral
composition.  The varieties selected, the cultural practices
followed, the fertilizers applied, all are decided on the basis
of yield expectation".  The manipulation of soil fertility in
accordance with this economic criterion can produce some curious
results, as instanced by the Missouri Agriculture Experimental
Station where it was found that by changing the ratio of calcium
to potassium, it was possible to increase the vegetative bulk of
soybeans by 1/4.  The only problem, but one hidden to the
consumer, was that this increase in vegetative mass represented a
reduction in the concentration of protein by 1/4, a reduction in
the concentration of calcium by 1/2 and a reduction in the
concentration by 2/3 over that in the smaller tonnage yield (see
William Albrecht, 1947, "Our teeth and our soils" ANNUALS OF
DENTISTRY, 6:208)


REFERENCES:

Fisher & Richter (1986) "Difference of organic and mineral
     fertilisers on Yield and quality of potatoes.  In H. Vogtman
     (ed), THE IMPORTANCE OF BIOLOGICAL AGRICULTURE IN A WORLD OF
     DIMINISHING RESOURCES.  Proc. 5th IFOAM Conference.
     
Lairon et al. (1986)  "Effects of organic and mineral fertilisers
     on content in vegetables of minerals, vitamin C and
     nitrates" [ibid]

EFRC (1989)  Quality of organically produced foods.  PROCEEDINGS
     OF INTERNATIONAL SCIENTIFIC COLLOQUIUM, feb, 1989, Elm Farm
     Research Centre; Newburg.

McSheehy, T. (1977).  Nutritive value of wheat groan under
     organic and chemical systems of farming.  QUAL. PLANTARUM,
     27: 113-27.

Vogtmann, H. (1984).  Accumulation of nitrates in leafy
     vegetables grown under contrasting agricultural systems.
     BIOLOGICAL AGRICULTURE & HORTICULTURE, 2: 51-68.

PMB (1989).  Characteristics of organically and conventionally
     grown potatoes.  SUTTON BRIDGE EXPERIMENTAL STATION ANNUAL
     REPORT, 1988, chapt. 10: 32-37.  Potato Marketing Board;
     Oxford.