[permaculture] Natural hydroponics, aquatic foodweb & quality food

Toby Hemenway toby at patternliteracy.com
Thu Apr 11 14:37:54 EDT 2013

A couple of further cogitations on hydro- and aquaponics. Plants have spent much more of their evolutionary history in water than on land. The first organisms that could be called plants appeared in the oceans about 2 billion years ago, and didn't emerge onto land until 260 million years ago. So they've spent over 80% of their existence in the sea, and still bear many of the adaptations to sea life—which is possibly why they take so readily to water culture. Land life is terrifically stressful; plants had to evolve waxy cuticles to keep from drying out, large root systems for taking in nutrients and water instead of small hold-fasts to anchor them, and on and on. Water culture relieves plants of many of the stresses of land life. To me, this makes arguments about water culture being "unnatural" pretty suspect. I could argue that it's much more natural for plants to grow in water, just as accurately as someone could argue that it's much more natural to eat ungrafted fruit or undomesticated plants. Humans spent more of our past eating wild foods than domesticated ones; plants spent an equally large percentage of their past growing in a nutrient solution without microbial intermediates and soil. Both are "natural" and may or may not be healthy ways to go. Circumstances are key.

I respect that some people don't like water-cultured foods, object to the technology, or have opinions about water-grown foods making them not feel as well-nourished, although I'd like to see a blind study: if you know you don't like something and then knowingly eat it, it's likely that you won't feel good eating it. That's not at all proof that it is lower in prana or nutrients or whatever; it just proves you don't like it. I prefer data to make up my mind.

The whole point to me here is not whether water culture is natural, or better, or as healthy as soil-grown food. It's that there are occasions when it can provide more healthy food than is normally available, and that's where it fits. A good example of this is in Denver, where a non-profit called the GrowHaus has taken over some cut-flower greenhouses and is growing thousands of greens in climate battery aquaponics. The GrowHaus is in a highly urban, low-income, mostly Hispanic neighborhood that is a true food desert: the nearest food store is a super-Walmart two miles away. Soils in the neighborhood are badly contaminated with industrial toxics: you don't want to garden there. I am certain, and I think a nutrient analysis would show, that the water-grown food the GrowHaus sells and gives away to their neighbors is far more nutritious than the crap they could buy at that Walmart or Safeway. This to me is a great illustration of  proper application of water culture of plants (and the way the GrowHaus does it, it builds the local community and economy).

Again, my diet is almost exclusively from soil-grown plants, and I don't see a role in my own life, now, for water culture. So I am not in any way advocating that it is universally a better way to grow food. I  am arguing that it can be a useful part of the toolkit and help transition to a healthier way of life. That for me is the bottom line, not, is it natural, is it permaculture, or is it sustainable, but: Is it a wise use of the resources we have now to move us toward where we need to go? To those folks in Denver, it's wiser than driving to Walmart.


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