I was wondering, what area space (m²) do I need to plant rice/bean in order to sustain one person for a year?
In How to Grow More Vegetables, John Jeavons claims you can sustain one person on 4,000 sf (372 m²), with 60% of that space dedicated to interplanted grains and legumes. The rest of the space would be taken up by high calorie root crops (30%) and vegetables (10%). That's with high soil fertility and in a climate with at least a six month growing season, so you can get in 3 plantings in the space.
I've used some of his methods with good results, but have never tried to grow all of my grains and legumes. I suspect in my climate, with a 3 1/2 month growing season, it would take significantly more space.
Jon Seymour, in his book
The Complete Book of Self-Sufficiency, mentions that 5 acres (about 2 hectares) of good quality, well drained land could sustain a family of 6 persons. The answer to the question will partly depend on whether or not one chooses to consume meat and dairy products and whether or not the land should also provide timber for energy. Seymour's five acre plan includes grazing and hay pastures, barley, beets and carrots for animal fodder, some woodland, a large vegetable garden, lots of beans, and so forth. For a complete description of how such a farm would work, see Seymour's book which can be found online.
Estimates from Morrison and Jeavons thus seem rather optimistic but differences are probably in part due to the choices that are being made.
That very much depends on how good a gardener you are. At least the following factors come into play
- soil fertility
- weather (esp. sun & rain)
- length of planting season
I remember a quote from Bill Morrison I heard from a recorded lecture that, with permaculture methods, one can sustain a family (2 adults, 2 children) on 50m² (with around 2 hours of gardening per week). I'd say, try it to see if it's true!
Permaculture usually plants high-carbs in form of potatoes. Rice certainly will require more time and more space (and more water).
Figures for land area have been stated, it is perhaps important to consider where that land is, its inherent soil quality and type, inclination towards the sun, altitude and longitude, precipitation - or available atmospheric moisture to be extracted - and short, medium and long term long term climate conditions. That's one heck of a lot of variables to ponder. A single figure can relate to one year at one place but be hugely different the next year, or at a different place. To give a single figure - a "One size fits all" approach is just plane silly.
Also it is vitally important to consider varying protein requirements. For your basic protein requirements legumes and plant growth tips and the germ part of things such as corn will go some way to providing basic requirements for those lucky enough to posses the requisite genes to allow their immune system to function correctly with this input. See: for clarification. (The question as to protein requirements in human populations is moot, after all we clean our fruit and vegetables before eating, getting rid of insects, slugs, a variety of eggs from those etc, which would have been part of our pre-historic diet)
For Manual workers, the young and expectant mothers I suggest that waste foliage can be converted by gastropods (A type of molluscan commonly known as snail). The Roman Snail as it is known in Britain used to be considered a staple part of the diet, it's efficient at producing compostable waste and is a good source of the full range of amino-acids required by growing humans from womb to adulthood, the shells can be crushed and added to reduce soil acidity and increase calcium content where necessary. Here's the preparation and a recipe for the giant African version. * Not for the faint of heart (Generally free-range.)
Supplementary protein and alternatives such as those insects found in rotting wood are considered tasty when cooked. See the bushcraftuk.com website archives for more details.
I have no opinion as to the flavor of the above protein supplements having never tried them myself.