Comment

Comment by Bob Campbell on July 4, 2013 at 6:08pm

Today I read an article

The Permaculture Solution – an Interview with Warren Brush

that said

Plus, it takes ten times the energy input for each calorie output in the American food supply system. We’ve spent something like two hundred and fifty million years of fossilized sunlight — in the form of fossil fuels — in the last fifty years. That’s something that can’t continue. It takes ninety-eight tons of plant material, degrading over millions of years of pressure, and heat, to become a barrel of oil, which is stored sunlight energy. We’ve designed all of our systems — energy, manufacturing, transportation, agricultural, how we move goods and water — around these intense forms of stored sunlight. That’s a finite resource.

After reading that I wrote an article on my blog today about the energy used to pump water and the return in calories from the harvested vegetables. http://chicogardens.blogspot.com/2013/07/energy-to-produce-vegetabl...

I calculated the required returns to break even for both aquaponics and soil gardening.

You seem to have a good technical and ecological approach to producing food, and I wonder if you might comment on use of fossil fuels for crop production.  Certainly I understand that we can't eat oil, but I find the number distressing.