In article ,
"DogDiesel" wrote:

Does a garden pay for itself ? Or is it cheaper to go to the grocery store.

how big you have to have to break even.

Factory farmed produce is definitely cheaper, in the short term, at the
store than you can grow yourself (economy of size).

The Omnivore's Dilemma: A Natural History of Four Meals
by Michael Pollan
http://www.amazon.com/Omnivores-Dile...als/dp/0143038
583/ref=pd_bbs_1?ie=UTF8&s=books&qid=1206815576&sr=1-1
(Available at better libraries near you)

BIG ORGANIC * 179

³The organic label is a marketing tool," Secretary Glickman said. ³It is
not a statement about food safety. Nor is 'organic' a value judgment
about nutrition or quality."

Some intriguing recent research suggests otherwise. A study by
University of California‹Davis researchers published in the Journal of
Agriculture and Food Chemistry in 2003 described an experiment in which
identical varieties of corn, strawberries, and blackberries grown in
neighboring plots using different methods (including organically and
conventionally) were compared for levels of vitamins and polyphenols.
Polyphenols are a group of secondary metabolites manufactured by plants
that we've recently learned play an important role in human health and
nutrition. Many are potent antioxidants; some play a role in preventing
or fighting cancer; others exhibit antimicrobial properties. The Davis
researchers found that organic and otherwise sustainably grown fruits
and vegetables contained significantly higher levels of both ascorbic
acid (vitamin C) and a wide range of polyphenols.

The recent discovery of these secondary metabolites in plants has bought
our understanding of the biological and chemical complexity of foods to
a deeper level of refinement; history suggests we haven't gotten
anywhere near the bottom of this question, either. The first level was
reached early in the nineteenth century with the identification of the
macronutrients‹protein, carbohydrate, and fat. Having isolated these
compounds, chemists thought they'd unlocked the key to human nutrition.
Yet some people (such as sailors) living on diets rich in macronutrients
nevertheless got sick. The mystery was solved when scientists discovered
the major vitamins‹a second key to human nutrition. Now it's the
polyphenols in plants that we're learning play a critical role in
keeping us healthy. (And which might explain why diets heavy in
processed food fortified with vitamins still aren't as nutritious as
fresh foods.) You wonder what else is going on in these plants, what
other undiscovered qualities in them we've evolved to depend on.

In many ways the mysteries of nutrition at the eating end of the food
chain closely mirror the mysteries of fertility at the growing end: The
two realms are like wildernesses that we keep convincing ourselves

Omnivore¹s Dilemma 180

our chemistry has mapped, at least until the next level of complexity
comes into view. Curiously, Justus von Liebig, the nineteenth-century
German chemist with the spectacularly ironic surname, bears
responsibility for science's overly reductive understanding of both ends
of the food chain. It was Liebig, you'll recall, who thought he had
found the chemical key to soil fertility with the discovery of NPK, and
it was the same Liebig who thought he had found the key to human
nutrition when identified the macronutrients in food. Liebig wasn't
wrong on either count, yet in both instances he made the fatal mistake
of thinking that what we knew about nourishing plants and people was all
we need to know to keep them healthy. It's a mistake we'll probably keep
repeating until we develop a deeper respect for the complexity of food
soil and, perhaps, the links between the two.

But back to the polyphenols, which may hint at the nature of that link.
Why in the world should organically grown blackberries or corn contain
significantly more of these compounds? The authors of Davis study
haven't settled the question, but they offer two suggestive theories.
The reason plants produce these compounds in the first place is to
defend themselves against pests and diseases; the more pressure from
pathogens, the more polyphenols a plant will produce. These compounds,
then, are the products of natural selection and, more specifically, the
coevolutionary relationship between plants and the species that prey on
them. Who would have guessed that humans evolved to profit from a diet
of these plant pesticides? Or that we would invent an agriculture that
then deprived us of them? The Davis authors hypothesize that plants
being defended by man-made pesticides don¹t need to work as hard to make
their own polyphenol pesticides. Coddled by us and our chemicals, the
plants see no reason to invest their sources in mounting a strong
defense. (Sort of like European nations during the cold war.)

A second explanation (one that subsequent research seems to suppport)
may be that the radically simplified soils in which chemically
fertilized plants grow don't supply all the raw ingredients needed to
synthesize these compounds, leaving the plants more vulnerable to
attack,

BIG ORGANIC * 181

as we know conventionally grown plants tend to be. NPK might be
sufficient for plant growth yet still might not give a plant everything
it needs to manufacture ascorbic acid or lycopene or resveratrol in
quantity. As it happens, many of the polyphenols (and especially a
subset called the flavonols) contribute to the characteristic taste of a
fruit or vegetable. Qualities we can't yet identify, in soil may
contribute qualities we've only just begun to identify in our foods and
our bodies.

Reading the Davis study I couldn't help thinking about the early
proponents of organic agriculture, people like Sir Albert Howard and J.
I. Rodale, who would have been cheered, if unsurprised, by the findings.
Both men were ridiculed for their unscientific conviction that a
reductive approach to soil fertility‹the NPK mentality‹would diminish
the nutritional quality of the food grown in it and, in turn, the health
of the people who lived on that food. All carrots are not created equal,
they believed; how we grow it, the soil we grow it in, what we feed that
soil all contribute qualities to a carrot, qualities that may yet escape
the explanatory net of our chemistry. Sooner or later the soil
scientists and nutritionists will catch up to Sir Howard, heed his
admonition that we begin ³treating the whole problem of health in soil,
plant, animal and man as one great subject."

So it happens that these organic blackberries perched on this mound of
vanilla ice cream, having been grown in a complexly fertile soil and
forced to fight their own fights against pests and disease, are in some
quantifiable way more nutritious than conventional blackberries. This
would probably not come as earthshaking news to Albert Howard or J. I.
Rodale or any number of organic farmers, but at least now it is a claim
for which we can supply a scientific citation: J. Agric. Food. Chem.
vol. 51, no. 5, 2003. (Several other such studies have appeared since;
see the Sources section at the back of this book.)

Obviously there is much more to be learned about the relationship of
soil to plant, animals, and health, and it would be a mistake to lean
too heavily on any one study. It would also be a mistake to assume that
the word ³organic" on a label automatically signifies healthfulness,
especially when that label appears on heavily processed and
long-distance


THE OMNIVORE'S DILEMMA 182

foods that have probably had much of their nutritional value, not to
mention flavor, beaten out of them long before they arrive at our
tables.

p.269

The fact that the nutritional quality of a given food (and of that
food's food) can vary not just in degree but in kind throws a big wrench
into an industrial food chain, the very premise of which is that beef is
beef and salmon salmon. It also throws a new light on the whole question
of cost, for if quality matters so much more than quantity, then the
price of a food may bear little relation to the value of the nutrients
in it. If units of omega-3s and beta carotene and vitamin E are what an
egg shopper is really after, then Joel's $2.20 a dozen pastured eggs
actually represent a much better deal than the $0.79 a dozen industrial
eggs at the supermarket. As long as one egg looks pretty much like
another, all the chickens like chicken, and beef beef, the substitution
of quantity for quality will go on unnoticed by most consumers, but it
is becoming increasingly apparent to anyone with an electron microscope
or a mass spectrometer that, truly, this is not the same food.
--
- Billy
³When you give food to the poor, they call you a saint. When you ask why the poor have no food, they call you a communist.²
-Archbishop Helder Camara
http://peace.mennolink.org/articles/...acegroups.html
http://english.aljazeera.net/indepth...130964689.html