Bart made the points about soil, which I believe should be the start point.
While our eye is, in the nature of our preoccupations, on our own stomachs,
the sustainability issue starts with soil nutrition.
Would people prefer, or be as well off nutritionally, on some science
fiction diet of pills providing 'essential nutrition' to the best of current
scientific ability to build such pills? I think the vote is going to be no.
Why then do we suppose that plants and animals depending on the soil can get
by on such thin stuff. I don't know how soil science is conventionally
taught, but I suspect that in the reductionist details, some of the broad
systemic issues may be skipped. My own view is that we would be well served
to commit much more effort to understanding the origins of life not just in
palaeontological terms, but in the relationship between clays, coacervates,
algae, fungi and bacteria, and their extraordinary associations with plant
roots. In other words, to recognise that our dependence on soil and plants
is much more than a nutritional chemical pathway. When we have an ability to
understand better, and describe for popular culture, just what is going on
there, then people will be more aware that plants are very complex systems,
with life properties going beyond crude nutrient assays. We are, again,
preoccupied by our majesty at the top of the food chain; but our processes
for nutrient uptake seem much simpler in many ways than what plants are
doing day by day.
Hydroponic vegetables allow us to make a couple of points of importance.
Because such plants are generally grown inside buildings, they may not be
vulnerable to insects, and so may not have pesticides on them (I don't
discount the importance of avoiding pesticides, but it's sort of a side
track from the core of what organic growing is about). But the hydroponics
will almost certainly NOT have been exposed to natural, unfiltered light.
And for the most part they are fed on crude nutrient solutions. Hydroponics
look great in the supermarket, but a lot of the 'look' derives from the fact
that confronted by uptake of a strong nutrient solution, plant cells will
seek to take up even more water - hence swollen cells, looking good on the
shelf, (much like older folk can look less wrinkly, by taking hormones that
cause fluid retention). That means that the plant is likely to consist of
more stressed cells and more crude nutrients - so an assay of such a plant
may show up more 'minerals', maybe balanced out by more water. And hey, this
chemically overloaded item is going to keep looking good in the supermarket,
as the water spray in the produce spray keeps up the osmotic frantics. I
tend to be more chemically sensitive than the average person. I get what
feels like a 'nitrate headache' (not so strong, but just the same headache
as I can get taking tiny doses of nitroglycerine, for cramp problems -
angina is the classic use of nitro, but it can also be used in other cases)
from some hydroponic lettuces. Of course, the stressed lettuce only has to
last a few weeks.
Experiment to suggest - we have done it by accident: buy one organic
lettuce, and one hydroponic lettuce. Put them in the same part of the
fridge. Go away for two weeks. The organic lettuce, in our experience, will
be there, whole and welcoming; the other item will be on the way to becoming
watery sludge.
Pears, especially nashi, the oriental pear, with even higher water content,
are among the best indicators of difference in taste and keeping quality, as
between conventional and organic. Our own organic nashi have a fresh,
complex flavour. Conventional nashi often seem to have a taste and smell
like a chemical fertiliser bag. I think taste is an excellent indicator of
nutritional value for the individual, far more sophisticated than the
printed info on box.
Dennis
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