permaculture

[christopher nesbitt <christopher.nesbitt@mmrfbz.org>]

Thank you, Toby, for your well written explanation of some of the biology 
behind aquaponics. 

Thank you, Kathryn, for taking the time to work to educate those who have 
misconceptions against aquaponics, and addressing each of their concerns so 
completely. 



_____________________________
Christopher Nesbitt

Maya Mountain Research Farm
San Pedro Columbia, Toledo
PO 153 Punta Gorda Town, Toledo
BELIZE, 
Central America

Country code 501-630-4386

www.mmrfbz.org
www.facebook.com/MayaMountainResearchFarm




On Oct 9, 2012, at 3:51 PM, Toby Hemenway wrote:

> Well-aerated, nutrient-rich water can grow vastly more microbes than any 
> soil. I used to run a fermentation lab, so I've done it, easily. This is 
> why wetlands are so important--and they work because wetland plants pump 
> out oxygen at far higher rates than most terrestrial plants, and nutrient 
> diffusion rates in water are far higher than in soil. Plus soil is mostly 
> rock or carbon, which displaces bacteria, while water doesn't displace 
> them--the sheer density of microbes in water can be far higher. The few 
> billion bacteria per gram of healthy soil are a fraction of what a healthy 
> wetland or an aquaponics system can achieve.
> 
> Like any system, aquaponics is not appropriate for every situation. But in 
> places where land is scarce (cities), conditions are unreliable (many 
> places), technical resources are more available than soil, and a number of 
> other situations, aquaponics can allow food--and dense protein--to be grown 
> where it otherwise can't. 
> 
> You can get rid of fungi and other diseases more easily than in soil 
> because you can circulate a treatment through the entire system very 
> quickly or even replace the water, unlike soil.
> 
> I'm grateful to Kathryn K for staying so level-headed and reasonable in the 
> face of some assumptions not well based in fact. I used to have a strong 
> prejudice against aquaponics, but it pretty well dissolved after I learned 
> more about it. I'm awfully fond of soil-based systems, but aquaponics has 
> its advantages in some places. It's a useful tool.
> 
> Toby
> http://patternliteracy.com
> 
> 
> On Oct 9, 2012, at 2:19 PM, John D'hondt wrote:
> 
>> 
>> I was obviously too fast again when I called a water environment basically 
>> anaerobic. That would only be the case in a static situation. Moving water 
>> can have enough oxigen to enable salmon to perform very powerful leaps.
>> However, if you had numbers of micro-organisms in water as high as in good 
>> soil your water would be anaerobic and it would look rather unclear and 
>> murky.
>> Those huge numbers in soil are important because in a good ecosystem like 
>> good soil, bacteria and fungi have very much closer relations with plants 
>> than just turning amonia into nitrate. It is known that micro organisms 
>> exchange complex molecules like amino acids and vitamins (B12 has been 
>> known 
>> for this for decades) with plants for plant made sugar. In some places 
>> like 
>> India people used sugar as sole fertilizer and saw no lack of nitrogen. I 
>> can well believe that for I used Sitka spruce saw dust (with virtually no 
>> nitrogen) on top of rock and could not find nitrogen being a limiting 
>> factor. Of course we seldom have a problem with too little rain here in 
>> Ireland and that helps.
>> Fungi/mycorrhizae live partly inside plant roots, exchange molecules and 
>> information and are known to protect plants from environmental stresses 
>> like 
>> acid rain and diseases caused by other fungi and bacteria.
>> 
>> I love my soil ecosystems for they enabled me to get rid of potato blight 
>> and crucifer clubroot without any chemical intervention and even without 
>> rotating crops much for 20 years. What do you do when your aquaponic 
>> system 
>> develops a disease problem? You probably have a better chance in Tassie or 
>> the US but here in Ireland blight and other fungal spores are everywhere. 
>> Still, how would you solve disease if it occured?
>> John
>> 
>> 
> 
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