permaculture

[Rain Tenaqiya <raincascadia@yahoo.com>]

There were a couple of points I'd like to "correct:"
 
1.  Municipal sludge is nasty-  If the waste stream is properly designed so 
that industrial toxins are not entering it and if the sewage sludge is 
composted properly with a good C:N ratio so that it gets hot, there will not 
be significant toxins or harmful organisms in it.  King County (Seattle area) 
has been doing this for years and uses it for growing wheat, landscaping, and 
forestry.  They report that the level of heavy metals in the soil is actually 
diluted by adding the composted sludge.  Unfortunately, most of the nitrogen 
in sewage is in the liquid part, so it is not being recycled.
 
2.  Exporting crops from farms can be sustainable because plants are mostly 
water, carbon, and nitrogen-  It is common knowledge that soil fertility 
declines after only one to three seasons of exporting crops, and this is not 
just because of the loss of nitrogen.  Phosphorus, potassium, and other 
nutrients are mined out of the soil by plants and must be returned (a basic 
permaculture principle).  Furthermore, in cases where a nutrient exists in 
sufficient quantities only in a certain strata of the soil or bedrock 
profile, it will be lost forever once plants that are being exported have 
integrated the nutrient into their tissues.
 
Most of the "solutions" to agriculture involve the use of fossil fuels to 
move stuff around.  Very few advanced horticultural or agrarian cultures have 
been able to sustainably farm for more than a few hundred years, and this is 
without the use of fossil fuels.  Besides the rape of the planet that fossil 
fuel use entails, we need to come up with ways of providing for ourselves 
once fossil fuels run out.  It is pretty sobering when you start to look at 
alternatives.  It takes a lot of space and work to grow enough apples to 
produce ethanol for even very modest transportation use, for example.
 
Rain

                
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