Monday, July 4, 2011

The Numbers of Sustainability: 3

So the "numbers" series is continuing to generate both interest and ire. Nice to know people are reading. . .

An email I received-- paraphrased:

"Jay, you've got no idea what you're talking about. My family has four 100 square foot raised beds and they easily grow half our food. That's for a family of four. . .maybe you need more practice gardening."

This fellow makes a partial living promoting and developing small garden beds. And he mows lawns, elsewise.

OK, that's fine, on the surface the claim sounds reasonable. But let's think about it a bit.

We can talk in terms of calories, and it would be very helpful, but no one wants to, because the numbers are irritating. We can talk in terms of pounds, but no one wants to weigh out and really quantify this either. So there's an attempt to keep numbers out of the conversation, but whoops, they're still there. Back of the envelope, and off the cuff, but still there. . .


We can assume that it costs perhaps 400 dollars a month at a reasonable minimum to feed an adult. If, as in this household they're 4 adults(two teens) that's netting 200 dollars a month(half their food) x 4, or 800 dollars a month. Times twelve, that's 9600 dollars a year in produce, out of 400 square feet, or a net yield of 24 dollars a square foot.  If we assume my numbers of net value(the produce likely worth 2 dollars a pound, as in greens, brocoli, etc.,) that's cranking out 12 pounds a square foot a year. Sustainably too! Organic!

It's all in the mulch, he says. I think it's in the bullshit.

A one acre property "gardened" at this level of proficiency would net the gardener, what, almost a million bucks a year in gross proceeds, and that's assuming that you lose some square footage to pathways and a tool shed(approx 40000 square feet times 24 dollars a square foot.)

Boy, if I could plant beans like that, I'd quit my day job!

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