I think there is often some confusion over the word “sustainable”. If you think about it, you will see that there is no particular emphasis on what kind of farming it means, as in “conventional” vs “organic”. What “sustainable” means is just that: can this method of farming be sustained over a long period of time?
The problem or rather, one of the problems, with most “conventional” crop farming is that it is NOT sustainable, in that it destroys the fertility of the soil, usually through salination due to irrigation, or destruction of “organic” materials in the soil. (My use of the word “organic” in that sentence has nothing to do with what people think of as “organic farming”, but rather with the actual structure/content of the soil.) Plants need certain chemicals to grow, but merely adding the “required” chemicals in the “recommended” amounts is not enough to maintain soil fertility. And it certainly doesn’t increase it. There are ways to deal with these issues without the sudden transformation of all conventional agriculture to “organic”, but so far agribusiness has preferred to “solve” problems by using more chemicals, etc.
We have come to depend on an agribusiness structure almost totally dependent on petroleum for the manufacture of fertilizers, the operation of farm equipment, and the transportation of supplies to the farms and the transportation of the crops to market. We can, so far, “afford” it. The price of food is rising faster than overall inflation, but food for North Americans is still very cheap, about 8 or 9 % of income on average. When, as seems inevitable to me, the price of oil begins to seriously impact the price of food, we might see some changes in the way Americans and Canadians grow and market food.
We are accustomed now to buying almost anything at any time of the year. When there are no strawberries in BC, I can buy strawberries from Chile. I can buy “fresh” blackberries right now at Costco, and “fresh” snap peas from Guatemala. What it has cost to produce these things, what it has cost to get them to me in February, makes for interesting speculation. Is this a “good thing”? To those who enjoy imported produce, I suppose it is. To those who are uninterested in the issues implicit in such trade, I suppose it is.
Organic farming is a growth industry. Yet much organic farming is “industrial” in its methods, even when devoted to soil conservation and health by use of organic methods and done without herbicides and pesticides. I can buy organic salad mix from California (and I do), but the same amount of oil is needed to get the trucks from California to here as for conventional California lettuce. The farmer will have needed petroleum to operate his machinery. But he will not have used petroleum-based fertilizers.
Can the world be fed without “conventional” agriculture? It is constantly asserted that it can’t. Certainly in the short term it can, but when land is destroyed by poor farming practices, where are we to get more land? When the price of petroleum has got so high that farmers in poorer countries can’t afford to buy the fertilizers necessary for them to grow food the “modern way”, what are they to do? When, as is inevitable, some plague affects corn, what are we to do for corn? Corn, that is Zhea mays is the most important crop in the world, and yet the number of varieties grown is pathetically small, leaving this precious crop vulnerable to disease.
I don’t think our future is going to see a reversal of history and that millions of people will have to return to the land to grow food. I think with some common sense and necessary changes in the way we grow food, it will be possible to keep feeding ourselves without destroying the soil. I think that as the price of oil continues to rise, the folly of buying blackberries in February will be seen to be the folly it is, and affordable only by the very rich. (In Roman times the Emperor could have anything he wanted, after all he could afford to pay for it. Fruits from Egypt in the winter, ice for sherbets in the summer.)
It is simply not possible for the Earth to feed everyone the way we eat in North America. There isn’t enough land, never mind anything else. We live too high on the hog, anyway. Our lives will change either voluntarily or otherwise.