permaculture

[KAKerby@aol.com]

OK, I've been gone for a number of hours, a bunch of emails on this topic  
have come in, and I'd like to address some of these statements in  turn.   
But it'll be in summary form, so hopefully no one takes  offense that I'm 
just trying to answer things as quickly as possible.

First, aquaponics is most definitely an aerobic setup.  The claims  made 
about faster growth are precisely because aquaponics is MUCH MORE aerobic  
than standard soil-based farming.  The roots are exposed to much greater  
rates 
and volumes of gas exchange, so poor gas exchnage is no longer a  
bottleneck for plant growth rates.  That exchange rate can be varied  
depending on 
both the system design and the cycling rate.  One of the three  major 
hydroponic and aquaponic methods, known as flood-and-drain, features  a 
container of 
planting media and intact plants which is repeatedly flooded,  then 
drained, then flooded again, at whatever cycle is appropriate for the  
plants.  So 
you could have system conditions ranging from near-saturation  to 
near-desert rates of moisture for the root zone, whatever the plants  need.  
With that 
system, each new influx of water fills the container, thus  driving out any 
atmosphere (mix of O2, CO2 and N2 and trace elements) from the  root zone.  
That "flood" stage is generally the shorter of the two  phases.  The longer 
"drain" stage draws atmosphere back down deep into the  root zone, for a 
dramatically faster gas exchange rate than would ever occur in  soil-based 
growing.  The other two most popular setups, Nutrient Flow  Technique and 
Floating Raft Technique, generally feature part of the root mass  submerged, 
and 
part of the root mass in an extremely high-humidity but  non-submerged 
atmosphere.  So again, there's no drowning or  anaerobic conditions.  If a 
hydro- 
or aquaponics system ever goes  anaerobic, something is very dramatically 
wrong.
 
Second, I concur wholeheartedly that soil is a precious commodity, and  
should be treasured as such.  So the comment that someone was turned off by  
seeing a photo of an aquaponics system in the foreground, then very tidy  
inedible landscaping in the background, is a philosophical objection I would  
share.  However, I have to point out that it wasn't a valid  indicator on 
whether aquaponics can or cannot be part of a sustainable  setup.  Rather, it 
was merely an indication of that particular person's  taste in landscaping.  
You could take that same setup, and put it in a poor  village in some distant 
poverty-stricken nation, and perhaps feel better about  the fact that it's 
feeding everyone in the village.  Same system.  And  there are countless 
variations on that system to match up with needs all around  the world.  So 
if 
some aquaponics fan had a front yard that didn't meet up  with your personal 
preferences for landscaping, that's hardly an indictment  against the 
approach as a whole.
 
Also on the topic of soils, I would point out that merely having access to  
soils does not guarantee that folks can grow what they need, as much as 
they  need, and when they need it, on those soils.  Or even if they could  
grow 
what they need during ideal years, conditions might be so unpredictable  
that they couldn't count on those soils to produce what they need, year after 
 
year.  We live in one of the most productive agricultural areas of the  
world.  We are greatly blessed that we can work with both forested and rich  
fertile floodplain soils.  We have a mild climate, with a nice long growing  
season.  But even here, there are things we can't grow reliably, including  
staples like corn and alfalfa.  Try feeding 100 head of livestock without  
those two staples, and you'll be up at night trying to balance your feed 
ration  with whatever you can scrounge instead.  Been there, done that.  We  
are 
very fortunate to be able to go out and buy those materials when we can't  
grow them.  But other families and other farms in other places aren't  nearly 
that lucky.  They must eat from whatever they can grow.  Even  when the 
soils are just right in terms of fertility, tilth, moisture,  temperature and 
solar exposure, one storm, one flood, one early frost or late  frost or any 
other combo of "bad luck" events, can wreck the crop.  In some  fortunate 
parts of the world, that's not a big deal.  We buy in what we  need to 
replace 
what we lost.  Other folks aren't so lucky, and they go  hungry.  Aquaponics 
removes a lot of that variability.  That's why we  want to use it here.  It 
would be our backup for those crops which are iffy  at best even in our 
prime agricultural area.  And it will allow us to grow  some critical crops 
which, despite our near-ideal setup, we still can't grow  here.
 
The question of equipment and volunteers and employees is a complication,  
which ironically makes aquaponics shine even brighter.  We are in WA state,  
USA.  It might surprise folks to learn that we CANNOT have farm volunteers  
here.  It's against state law.  We can either have interns, that must  be 
enrolled in a public school and taking a class for credit in which we are a  
formal part of the curriculum, or we can have employees, paid at least 
minimum  wage, and fully insured under our farm insurance coverage plan.  And 
now 
 proposed federal law, which didn't pass this year but very well might in 
the  future, states that family members must be "immediate family", ie, 
spouse,  children and parents.  Cousins and aunts and uncles and  
grandparents/grandkids, etc, would not be considered family, and thus would 
be  required to 
be hired, for at least minimum wage, with full insurance coverage.  So as 
neat as it sounds to have some big farm in the family, working that  farm 
requires some careful thought because manpower is no longer quite so easy  to 
access.  
 
OK, so if we can't have lots of people, let's get some large-scale  
machinery in here instead.  Sadly, that's not very practical  either.  A 70hp 
tractor, and all the implements listed in a previous  post, would cost more 
than 
our house is worth.  We have a 20 hp tractor  that was manufactured the same 
year my dad was born.  Our haying equipment  was made when draft animal 
power was still in use in the USA, and that equipment  can be drawn either 
with 
our small tractor or a team.  We shopped very  carefully for that 
equipment, and saved a great deal of money, by buying smaller  than everyone 
said 
we'd need.  We didn't finance any of it.  Yet  it still set us back quite a 
bit 
financially, and we still have repairs to make  before any of it is field 
ready.  So yes, a lot of folks are having serious  problems getting into 
farming, because even if they have access to land they  need either manpower 
or 
machinery to work it, and both of those options are not  nearly as easy to 
come by as they used to be.
 
Which brings us to aquaponics.  Because machinery and manpower are  both so 
expensive here, we have to make the absolute best use of our  time, at a 
scale that we can reasonably accommodate without either equipment or  
employees.  One of the major questions we're facing right now with this  
bigger 
farm, is whether we want to take on all that extra work, knowing that  we'd 
have 
to have employees (thankfully, we'd have access to their machinery  instead 
of buying it ourselves).  But I can produce the same products via  
aquaponics that I manage by myself, as I can with field crops requiring a lot 
of  
expensive equipment and/or hired help.  That's because of two things.   
First, 
it is so much more productive per square foot than any soil-based  system.  
Second, it allows for harvests in small batches, rather than  one 
all-or-nothing harvest.  I've known of growers who raise just enough  feed 
for their 
animals to last one day with aquaponics.  They plant one  tray per day, they 
harvest one tray per day.  The rest of the trays are  growing and don't 
need to be messed with other than watering.  The manpower  is minimal, and 
they're doing the work I'd have to have machinery AND manpower  to 
successfully 
harvest in the field.  And that's only if the weather  cooperates.  If the 
weather doesn't cooperate, or the machinery breaks  down, or the manpower 
quits or is busy or sick or otherwise unavailable, that  harvest rots.  
Shucks, 
that's too bad.  And most years, at least one  of those issues comes along. 
 Try telling your family that they don't get  to eat because the tractor 
blew a hydraulic seal.  Aquaponics has its own  list of woes, but they don't 
tend to be quite so dramatic, so costly, or so  all-or-nothing in scale.
 
Finally, I know a lot of folks will puzzle about this next question, but we 
 believe it is utter folly to farm with anything less than profitable  
outcomes.  We subscribe to the theory that for any farm to be truly  
sustainable, it must meet the Three E's: Environmental, Ethical and  
Economical  
Sustainability.  So everything we do here, is for the love  of the land and 
love 
of the life, but it's also how we pay the bills.  If  we can't pay the bills, 
for instance if we borrowed money to buy all that nice  big machinery, we 
won't be farming very long.  And then all this nice talk  about sustainable 
this-n-that goes right out the window.  The next guy  comes along and 
converts all this wonderful farmland into condos.  Or a  junkyard for old 
cars.  Or 
a landfill.  Or whatever.  I know some  folks farm because they want to.  
Some folks farm because they have to,  since they can't get food otherwise.  
We farm because we feel called to do  so, but we must meet those 3 E's in 
order to continue doing so for any  length of time.  Again, aquaponics 
removes 
a lot of the harvest  uncertainty, and thus the financial uncertainty, from 
this gig called  farming.  That means it's not merely a nice tool in the 
toolbox.  For  us that means it's borderline essential.  Farming without it 
is 
riskier  than it needs to be.
 
I guess after all this, I would suggest that folks can decide they're not  
interested in aquaponics, and that's fine.  They can decide they don't want  
to use aquaponics, and that's also fine.  They can decide wow there's more  
here than they realized, go learn about it, and maybe implement it or maybe 
not,  according to their own needs and interests.  All that is fine.  Where 
 I tend to get twitchy, is when folks hear the term "aquaponics", and they 
only  know a little about it, and they start making assumptions about it, 
and then  they start making opinions and decisions based on those 
assumptions. 
 Or  worse, start advising people based on those assumptions.  I would 
strongly  encourage folks to learn about this approach before forming 
opinions 
about  it.  Don't just go with what you've seen in the headlines, or on 
Youtube,  or heard someone say that someone said that someone said that it's 
just 
a bunch  of hooey.  Either learn about it, and speak from a position of 
knowledge  and experience.  Or simply say "well, I've heard about it but 
don't 
know  much about it, so I can't really say."  That's all I ask.
Kathryn  Kerby
frogchorusfarm.com
Snohomish, WA
 
 
 
In a message dated 10/8/2012 2:23:18 P.M. Pacific Daylight Time,  
dhondt@eircom.net writes:


My  problem with aquaphonics is not just disolved chemicals aka nutrients.  
Soil is an ecosystem consisting for at least ten % out of microorganisms  
and 
often a lot more. To a large extend these soil organisms are aerobic.  It 
is 
as good as impossible to maintain a large aerobic community in  water.
john

> On 10/7/2012 9:52 PM, Scott Pittman  wrote:
>> I too have serious misgivings about aquaponics.  It is  always presented 
>> as
>> some kind of perpetual motion  machine that provides for all its needs 
>> within
>> the  system, which I doubt.  I also do not believe that it could  
possible
>> have the nutrients necessary for providing wholesome and  nutritious
>> foodstuff.  We are talking about the primary  nutrient source being fish 
>> dung
>> in this closed  system, where does the selenium, calcium and phosphorous 
>>  come
>> from?  The co-evolution of plants with soil organisms  and minerals has
>> created the human nutrition story and without  soil I think the actual
>> nutrient content will be woefully  inadequate.
>
> I would never try to grow food for myself in an  aquaponics system unless
> its nutrients came from extracts of  soil-based systems (don't quite know
> how that would work given the  anaerobic aspects of aquaponics systems. I
> did find through a Google  search a site with pictures of a soil-based
> aquaponics system but they  were growing ornamental aquatic plants in
> submerged perforated barrels  with a soil mix in them. The root crowns of
> the plants were slightly  above water level.
>
>> I would love to see some data on  nutrient content of hydroponic vs soil
>> based  vegetables.
>
> There is probably no comparison with the nutrient  dense food crops grown
> in enriched soil with balanced nutrients and  minerals.
>
>> I would also point out that both the rice paddy  system and chinampa 
>> systems
>> are soil based systems  with a lot of water to maintain growth they are 
>> not
>>  by any means hydroponic or aquaponic. You might also throw in the  fast
>> disappearing mangroves as an example of aquaponics but again  you would 
be
>> wrong.
>
> In Eritrea they are developing  an array of sustainable farming systems
> that use sea water, They  impound water in lagoons and grow shrimp in
> them. That nutrient-rich  water is released down stream to fertilize and
> irrigate salt-tolerant  land based crops. These crops are used to human
> as well as livestock  feed and to make rope or cloth. They are also
> propagating, planting  and harvesting mangroves for firewood, livestock
> feed and construction  wood. They are not reducing the populations of
> mangroves along the  coastline where their project is located. There is a
> PBS documentary  about this well worth watching, maybe viewable online or
> for $$$ for  the dvd.
>
> LL
>
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