Often asked, yet difficult to answer: How much land does one person need to sustain themselves?
Many factors come in to play such as climate, diet (vegetarian/meat eater), quality of soil, and preferred farming technique.
Over the past couple of years I have been wondering about this very same question - how much land would be enough to maintain a healthy and sustainable lifestyle? What skills might I need to learn, and what preparations might I need to make? Would a small cluster of family and friends be more appropriate, or an entirely individual approach? Is there a ratio, per head? Is it related more to land yield and local resources? The sun, the availability of water? The soil health and the ability to grow food?
The simple answer is 0.07 hectares of land per person. Based on a largely vegetarian diet, on arable land with little or no degradation, adequate water supplies and a good working knowledge of farming techniques such as planting, fertilizing and irrigating.
On small lots, the farming techniques chosen can greatly enhance and improve productivity.
Many of the techniques that comprise the biointensive method were present in the agriculture of the ancient Chinese, Greeks, Mayans, and of the Early Modern period in Europe. Alan Chadwick brought together the Biodynamic and French intensive methods, as well as his own unique approach, to form what he called the Biodynamic-French Intensive method. The method was further developed by John Jeavons and Ecology Action into a sustainable 8-step food-raising method known as "GROW BIOINTENSIVE."
John Jeavons wrote a book called 'How to grow more food than you thought possible on less land than you could imagine'. He included estimates on yield per square foot for a wide range of crops using his french intensive biodynamic approach (compost, double dig, clean cultivation, frequent irrigation etc..). His system assumes unlimited nutrient, carbon, and water inputs. He figured 1/4 acre for vegetarian diet with grains and legumes as the core and yearround vege production in central california, (USA zone 9?). The vege's don't take up much space. You could get you vitamin needs off of weeds if you had to, but 1 year of protien and complex carbos (grain and dry beans, maybe potatos) is the hurdle.
So... in short... the footprint is inversely proportional to the amount of energy/nutrient/water subsidy you can gather from your neighborhood. Contemporary permaculture designs on small sites typically takes advantage of your neighbors waste.
But if everyone is scavenging nutrients and organic matter, then the game changes. I recently read that your urine contains enough nutrients to produce a grain crop to feed one human for a year.
The biointensive method is an organic agricultural system which focuses on maximum yields from the minimum area of land, while simultaneously improving the soil. The goal of the method is long term sustainability on a closed system basis. It has also been used successfully on small scale commercial farms.