There is a very narrow group of annuals, however, that grow in patches of a single species and store almost all of their income as seed, a tight bundle of carbohydrates easily exploited by seed eaters such as ourselves. Under normal circumstances, this eggs-in-one-basket strategy is a dumb idea for a plant. But not during catastrophes such as floods, fires, and volcanic eruptions. Such catastrophes strip established plant communities and create opportunities for wind-scattered entrepreneurial seed bearers. It is no accident that no matter where agriculture sprouted on the globe, it always happened near rivers. You might assume, as many have, that this is because the plants needed the water or nutrients. Mostly this is not true. They needed the power of flooding, which scoured landscapes and stripped out competitors. Nor is it an accident, I think, that agriculture arose independently and simultaneously around the globe just as the last ice age ended, a time of enormous upheaval when glacial melt let loose sea-size lakes to create tidal waves of erosion. It was a time of catastrophe.And what’s the net benefit?
Corn, rice, and wheat are especially adapted to catastrophe. It is their niche. In the natural scheme of things, a catastrophe would create a blank slate, bare soil, that was good for them. Then, under normal circumstances, succession would quickly close that niche. The annuals would colonize. Their roots would stabilize the soil, accumulate organic matter, provide cover. Eventually the catastrophic niche would close. Farming is the process of ripping that niche open again and again. It is an annual artificial catastrophe, and it requires the equivalent of three or four tons of TNT per acre for a modern American farm. Iowa’s fields require the energy of 4,000 Nagasaki bombs every year.
I’ve already mentioned that we humans take 40 percent of the globe’s primary productivity every year. You might have assumed we and our livestock eat our way through that volume, but this is not the case. Part of that total—almost a third of it—is the potential plant mass lost when forests are cleared for farming or when tropical rain forests are cut for grazing or when plows destroy the deep mat of prairie roots that held the whole business together, triggering erosion. The Dust Bowl was no accident of nature. A functioning grassland prairie produces more biomass each year than does even the most technologically advanced wheat field. The problem is, it’s mostly a form of grass and grass roots that humans can’t eat. So we replace the prairie with our own preferred grass, wheat. Never mind that we feed most of our grain to livestock, and that livestock is perfectly content to eat native grass. And never mind that there likely were more bison produced naturally on the Great Plains before farming than all of beef farming raises in the same area today. Our ancestors found it preferable to pluck the energy from the ground and when it ran out move on.Sure, we replaced all that with plants we (or our animals) could eat. We did so at the expense of the exhausting the soil. Native Americans may have used slash-and-burn agriculture, but they mixed crops and used manure for fertilization, and they were few enough that there was time for recuperation. With modern populations, there’s no recovery. Instead:
…only now when the vault is empty we fill it again with new energy in the form of oil-rich fertilizers. Oil is annual primary productivity stored as hydrocarbons, a trust fund of sorts, built up over many thousands of years. On average, it takes 5.5 gallons of fossil energy to restore a year’s worth of lost fertility to an acre of eroded land—in 1997 we burned through more than 400 years’ worth of ancient fossilized productivity, most of it from someplace else. Even as the earth beneath Iowa shrinks, it is being globalized.Manning points out that this globalization of factory farming and fossil fuel production sweeps more people off the land and thus makes more poor people, who breed faster, thus producing the population explosion that has doubled the world’s population since 1960. That is not coincidentally when the “green revolution” got underway; the same well-intentioned attempt to produce food production that has been co-opted by monoculture monopolists and factory agrobusiness.
Distributed diverse sustainable agriculture is possible, and it can produce as much or more food than factory farming. Maybe we’ll get to it before we get back to Plato’s lament:
…in comparison of what then was, there are remaining only the bones of the wasted body, as they may be called, as in the case of small islands, all the richer and softer parts of the soil having fallen away, and the mere skeleton of the land being left. But in the primitive state of the country, its mountains were high hills covered with soil, and the plains, as they are termed by us, of Phelleus were full of rich earth, and there was abundance of wood in the mountains. Of this last the traces still remain, for although some of the mountains now only afford sustenance to bees, not so very long ago there were still to be seen roofs of timber cut from trees growing there, which were of a size sufficient to cover the largest houses; and there were many other high trees, cultivated by man and bearing abundance of food for cattle. Moreover, the land reaped the benefit of the annual rainfall, not as now losing the water which flows off the bare earth into the sea, but, having an abundant supply in all places, and receiving it into herself and treasuring it up in the close clay soil, it let off into the hollows the streams which it absorbed from the heights, providing everywhere abundant fountains and rivers, of which there may still be observed sacred memorials in places where fountains once existed; and this proves the truth of what I am saying.— Plato, Critias, c 360 B.C.E.