Sewage
waters a tenth of world's irrigated crops [New Scientist]
Nothing wrong with that in principle, of course. Closing the farm to
city to farm nutrient cycle makes good sense. (Recalls to me my masters
thesis, back in the long ago, looking at the potential nutrient balance
of Washington DC's sewage stream and the ag region that supports the
city, which in turn lead to my current work with business and regional metabolism and 'material flow analysis' and key performance indicators.)
But good 'in principle' can be bad in application. The story talks of
raw sewage applied to crops like lettuces and greens that are eaten
without cooking, when it should be limited to crops that won't get
irrigation splash -- or better yet, on feed crops that will transit any
human sewage through an animal gut. Meanwhile, wash your vegetables, folks,
especially the imported ones.
The other problem: sewage from cities with heavy industry, or combined
storm and sanitary sewers that flow automobile emission and brake ware
particulates into the flow, will feed heavy metals into the crops, and
into you.
So, as is so often the case, the solution isn't just a technology or
material swap, but a system-level change. Organic agriculture isn't
just about organic waste; it's about an 'organic' as in 'integral'
approach to agriculture and food systems.
8:02:37 AM 
|
|
