Tuesday, February 7, 2012

Factoids About Food And Farming

Researching food production for an eco-village operating manual, I came across these factoids, mostly in a book by John Jeavons, called How to Grow More Vegetables than You Ever Thought Possible:

The world has about one human lifetime of soil left, assuming industrial farming practices;

The world has about nine thousand square feet of arable land per person;

Nineteenth century Chinese practices allowed production for one person on four thousand square feet;

Jeavons and his colleagues at Ecology Action in Willits, California, can grow one person’s entire diet on five thousand square feet, with a six month growing season, and winters that allow them to grow grain over the winter;

Jeavons’ practices build soil rather than deplete it;

These practices require fifteen minutes (or less) per day, per one hundred square feet, translating to ten hours (or less) per day, per person, assuming the Chinese level of production.

Monday, February 6, 2012

Reading Environment, Power, and Society

I've been reading Howard Odum's Environment Power and Society. I don't read technical stuff well. Odum says that it's a work for popular consumption. I see how it could be more difficult, but a lot of new concepts come at you on each page.

Odum's goal for the book is to communicate a "macroscopic" -- as opposed to reductionist -- view of the world. He discusses the flows of power in ecosystems -- of which human economy is an example -- and suggests that human survival depends upon understanding the energetics of systems. He writes, "Since decisions on such matters in the arena of public affairs are ultimately made according to the beliefs of the citizens, it is the citizens who must somehow include the energetics of systems in their education."

I'll bite. I'm happy to be able to run my eyes over Odum's discussions of the power flows in various ecosystems. I'm grateful to him for providing a vocabulary of symbols used in network diagrams, such as the one above, which illustrates the flows of carbon in a microcosm. P=gross photosynthesis. R=respiration. Hexagons are self reproducing systems, either organisms or populations. The bulge on the left indicates plants as labeled. The things with roof are supposed to look like tanks, and stand for storage.