In a world of peak oil concern, this was inspiring! A little long but have a look:
Some notes about organic growing:
It takes approximately
1800 square feet (a manageable backyard garden) of land to support one human being living on grains
3600 square feet (just less than 1/10 acre) to support someone living on potatoes
13,500 square feet (.31 acre) for someone living on milk,
36,000 square feet (.83 acre) for someone living on pork
90,000 square feet (2.07 acre) for someone subsisting entirely on beef
"The Natural Way of Farming: The Theory and Practice of Green Philosophy" by Masanobu Fukuoka
Note that none of these is entirely healthy - a mix is needed. Also note than the biggest change that we need to make now (and that we will have to make by the end of the century) is to eat less meat.
On the islands of Java and Bali, approximately 1 person is fed per acre.
Somewhere (sorry - I haven't been able to re-locate it yet) it is claimed that a half acre (21780 sq ft) can fill the needs of a typical Japanese family. (A 35 year average household size of 3 means that each person needs 7260 sq ft or .17 acre)
John Jeavons has discovered that approximately 4000 sq ft can feed 1 person (with a little more in less than ideal conditions...like Wisconsin winters!!). This is about 10 people per acre, the same as in the video, and it is achievable because Jeavons uses the 'interplanting' methods described in the video.
For more on Peak Oil and it's impending fallout, click here, here, or here.