Mick Fisch wrote:The article makes it clear to me. I was wrong. Following the authors logic, everyone should grow nothing but potatoes, because they produce more kg/hectare. Who could argue with the logic of that? Simply look at the kg/hectare, that will obviously show which is best. Hope you like your boiled potatoes plain, because in his scenario that's most efficient.
This is a common issue in comparing agricultural systems of any kind. I run a small organic farm part time - 2 3/4 acres of veggies, plus some ducks, geese, alpacas, and a few small areas of what I call "grazing gardens," but would be called a forest garden by most typical permies, which are just starting to produce fun things - peaches, nectarines, pears, nanking cherries, medlars, various mints and thymes, hardy almonds being our current yields there, with much work to go. I'm in the middle of a big ag region, ruled by GMO corn mostly. While I'm trying to budget money and labor to put in a mixed-species impenetrable hedge/living fence, my neighbors are cutting and burning miles of windbreak treelines to extend their center pivot irrigation systems from 1/2 mile to 2650 feet.
When we talk about sustainability, I am always confronted with "GMOs are needed so we can produce more food on less land. Organic production can never produce enough to feed the world." But I look at it this way - my across the ditch neighbor grew corn, like everyone else - 42 acres, yeilding 7,180 bushels. That's better than the state average last year, 171 bushels per acre. Google says a bushel of corn weighs 56 pounds, so that's about 9575 pounds of corn per acre. My potato plot was 1/8 of an acre, and I harvested 5240 pounds of potatoes, 120 pounds of milky oats, and 32 dozen duck eggs from that 1/8 acre. So his yield per acre was 9575 pounds of "food" (of course, it's as likely to be ethanol as a snickers bar or twinkie...), while I had 42,880 pounds +256 dozen duck eggs per acre.
That argument is not accepted, because I grew something different, and you can only compare one variable at a time (what they mean is that you should only have one independent variable in a controlled experiment, but they don't remember their high school science classes very well). Thus, to their way of thinking (and to a lesser degree, in the article), what you have to do is grow a huge monoculture of chemical corn next to a huge monoculture of organic corn, and compare yields. But when you're talking about a system
of production, that's an invalid comparison.
If we want to compare systems, we need to look at multiple year trends of apples-to-apples comparisons to evaluate input and output of the systems themselves, and it's going to need to be something more complex than "pounds of food." I would propose comparing something like the following:
Non-energy Inputs -> seed/plant material, fertilizer, irrigation water, pesticides, equipment/machinery (pro-rated portion of expected life span)
Energy Inputs -> Fuel, Labor
Nutritional Outputs -> some of the widely-recognized-as-important nutritional measures. I'd recommend Calories, Fat, Cholesterol, Sodium, Potassim, Carbs, Protein, Vitamin's A & C, Calcium and Iron as a reasonable subset
Positive Non-Food Outputs -> would vary, of course. But could include firewood, dies, fiber, property value increase, etc.
Negative Non-Food Outputs -> Water pollution, air pollution, property value decrease, etc.
With that, you could then have the data you need to compare two systems on the basis of what normal people care about (note that most normal people don't really care about the soil...). If you wanted to distill that to a single which-is-better number, you could simply monetize everything:
$nutritional Outputs + $Positive Non-Food Outputs - $Non-energy inputs - $energy inputs - $Negative Non-Food Outputs = $value added by the system
In reality, of course, you'd find that you can't even reduce it that far, because it will all be contextual for a given local area. And even with that, let's say you found the most "$value added by the system" system was you-pick gooseberries. It's not like everyone in the area cold start a you-pick gooseberry farm and provide the community with a sustainable diet. What you could find, though, is something like "gee, it looks like our local food shed is not producing enough vitamin A, and consequently people are having problems with nyctalopia." So there would be value in a system which produces an increase in vitamin A in the local diet. You could then compare which system both addresses that issue and provides the best overall balance: GMO Golden Rice monoculture, or a diversified farm producing sweet potatoes, spinach, collards, kale, dandelion greens, and winter squashes sheltered by a food forest high in apricots that sustains a population of geese (whose eggs and livers are pretty high in vitamin a).
Reductionism is problematic in comparing food production systems, and is a realm in which permaculture simply will never be able to "prove" its value objectively.