"It takes about 15,000 to 30,000 square feet of land to feed one person the average U.S. diet. I've figured out how to get it down to 4,000 square feet. How? I focus on growing soil, not crops."
That's organic/sustainable gardening guru and soil expert John Jeavons, author of the book "How to Grow More Vegetables Than You Ever Thought Possible On Less Land Than You Can Imagine," talking to the San Francisco Chronicle a few years back (via Grist). Jeavons has spent the last 30 years touting small-scale, sustainable, organic farming--a method of closed-loop crop production he has dubbed "biointensive farming."
Basically, biointensive farming incorporates many of the same practices as biodynamics, and takes them a few steps further. In addition to double-digging (tilling beds to a depth of 24 inches for greater aeration), planting in space-saving hexagonal or triangular patterns, planting complementary crops in the same space, and composting, farmers or gardeners employing biointensive methods use higher-energy crops (such as root crops) to increase the amount of calories a small piece of land will produce, grow some crops for use exclusively as compost (such as rye and alfalfa), and practice strict crop rotation to preserve soil productivity, among other things.
Some of biointensive farming's practices strike me as impractical on both a small and a large scale--human-waste composting is never going to become all that popular, for example, and I can't see many people doing the kind of intensive calories-per-square-inch calculations Jeavons calls for. Still, the method has some major advantages over conventional farming--the largest and most obvious being, of course, that it allows farmers to produce far more food per acre. That's a huge boon for home gardeners, like me, with little farmable land but a strong desire to get off the factory food grid. And it has exciting implications for subsistence farmers in places where arable land is scarce and growing scarcer--places like Kenya, Mexico, and Argentina, where Jeavons' methods are being used by thousands of small-scale farmers.
Stretching the productivity of a small amount of space is one way to increase harvests. Stretching out the growing season is another. According to a recent article in the New York Times, "extreme season extension" is growing in popularity as demand for local food increases. Using unheated low metal hoop houses and double-row covers, some farmers in the northern United States have managed to extend the season for certain produce through the spring, making crops like spinach and herbs available locally year-round. Hoop houses, it turns out, are cheaper than greenhouses; doubly so since, as temporary structures, they aren't subject to property taxes. Another season extension technology is called a high tunnel, which can be large enough to accommodate a tractor. With the popularity of both methods increasing, we may soon see local, organic strawberries on store shelves--in January.
It shouldn't matter what some people have in their heads about composting waste (sewage) - there isn't anything else feasible to do with waste than properly compost it. What tends to be done with it now is way more disguisting than turning it into non-smelly crumbly stuff.
Compost toilets are much easier to build and install, especially in rural places and especially even moreso in places that have no toilets, than any other kind of plumbed waste disposal. Plus theres load of composting loos on sale for indoor bathroom use.
Two other things that by demonstration have shown to significantly increase crop yeilds, are application of rock dust to soils, and use of a water-energising product (based upon research by Viktor Schauberger):
Related: see also information on the use of correct agricultural and horticultural tools,
With the rock dust application, the source of which is from quarries and costs little to nothing (obviously not including environmental impacts of the quarrying itself - this is more about putting some aspect of that to good use), the sizes of crops produced really are huge - like those champion giant-veg competitions.
Another way to improve soil fertility that has additional environmental benefits, is to use lava rock - it's very mineral rich, and its harvest can speed up the regrowth of plants in areas where there have been devastating eruptions.
Further information on much of the above comments:
For those who have not yet had the pleasure of reading the Humanure "bible" see: http://weblife.org/humanure/default.html
It really isn't quite as bad as the Flush Toilet Industry wants you to believe... The Flush Toilet Industry-- which is the 1st or 2nd highest domestic spending program each year: for sewer pipes and "waste" disposal systems (the other is highways).
We have been hijacked in the privy.
We are forced to pay taxes for a system that not only consumes pure water and looses mined finite (but recycle-able) nutrient deposits like phosphorus, but burns fossil fuels to turn it all into anaerobic toxic waste (originally known as "Blackwater" - long before the now famous American mercenary killer corporation).
No wonder corrupt politicians and "contractors" and "the Mafia" have been notoriously involved in this multi-billion dollar "service" for as long as anyone can recall. It is time to kick out the parasites and reclaim our poop, and close the nutrient cycle for our sustainability. Humanure is the low energy, clean, safe, non-smelly, valuable, natural, way to deal with our body's natural output... and turn it back into fertilizer and food, again... so we can sustain ourselves in a closed loop.
There are no living paths in nature that go one way and stop. If they didn't loop, they would be one way dead ends. Even our street system considers that an impossibility.
Erica, I would like to add one more interesting agricultural approach, to counter the bio-intensive farming method you talk about - which indeed sounds as a very intensive to do :o) (I won't go into the human waste discussion...)
I found out about this after reading another article about bio-intensive farming here on Worldchanging, and it reminded me of something that Janine Benyus wrote about in her book Biomimicry: using perrenial crops that grow stronger every year in stead of annuals that require you to destroy the soil every year again. For people that like as much result with as little input as possible (like me), this is ideal.
It is called Forest Gardening, and it basically emulates a mature ecosystem in which every bit of energy is used in every possible way. This means that there will be hardly any 'weeds' (for as far as your definition of weeds goes), because if you design it properly all the nutritional and energetic niches will be filled. This means that it requires very little maintenance.
More importantly, because it will consist of mostly perrenial crops, the whole garden will be very resistant against different types of weather, storms, etc. To me it makes a lot of sense - I have to admin I did not try this method yet but I'd love to hear from anyone else that has. What I've read so far sounds very good: low maintenance, high resistant. I don't know about the yield compared to the numbers above though, but since they talk not only about food it might be hard to compare...
Composting loos are really no problem. I've had one for my own personal use for about fifteen years now. They're completely inoffensive, used right, and have this attractive piney, sawdusty, woodland aroma, when they have any at all. All my production goes into my raised beds, under substantial layers of Ruth Stout-style mixed mulch materials cut by my scythe, from my local neglected waste lands. I wouldn't dream of doing anything so crazy as flushing this precious stuff down the sewers.
Urbanites have such a grotesquely artificial life that many of them think that they couldn't live without flush loos. But when they visit my friend Eric Maddern's magical retreat place in the mountain forest, beside Afon Fachwen ('Little White River') tumbling down to LLyn Padarn (Saint Padarn's lake)in the mountains of Cymru Gogledd (North Wales) they find that the only easement thing available is a two-room, four-chamber composting toilet looking out over the woodlands -- 'the loo with the view' -- which, amongst other delights, has a simple but effective separation shaping built in to it's design, so that liquid and solid wastes are separated automatically, without you having to think about it (both men and women), and the gardens and fruit trees get this terrific, rich, and wholly inoffensive bonus every year or so.
To see pictures of it, and the rest of Eric's truly wonderful place, google 'Cae Mabon' It mean's Mabon's Field: the sacred sanctuary of the old Celtic god Mabon. An interesting thing: This is one of the few places I've ever seen where the beautiful, alluring pictures are actually outdone by the place itself: the reality is actually even more magical than the pictures seem to suggest!
And everyone just loves the no-flush, composting loos: instant conversion.