The Omnivore's Dilemma - Michael Pollan [24]
Haber’s story embodies the paradoxes of science: the double edge to our manipulations of nature, the good and evil that can flow not only from the same man but the same knowledge. Haber brought a vital new source of fertility and an awful new weapon into the world; as his biographer wrote, “[I]t’s the same science and the same man doing both.” Yet this dualism dividing the benefactor of agriculture from the chemical weapons maker is far too pat, for even Haber’s benefaction has proven decidedly to be a mixed blessing.
When humankind acquired the power to fix nitrogen, the basis of soil fertility shifted from a total reliance on the energy of the sun to a new reliance on fossil fuel. For the Haber-Bosch process works by combining nitrogen and hydrogen gases under immense heat and pressure in the presence of a catalyst. The heat and pressure are supplied by prodigious amounts of electricity, and the hydrogen is supplied by oil, coal, or, most commonly today, natural gas—fossil fuels. True, these fossil fuels were at one time billions of years ago created by the sun, but they are not renewable in the same way that the fertility created by a legume nourished by sunlight is. (That nitrogen is actually fixed by a bacterium living on the roots of the legume, which trades a tiny drip of sugar for the nitrogen the plant needs.)
On the day in the 1950s that George Naylor’s father spread his first load of ammonium nitrate fertilizer, the ecology of his farm underwent a quiet revolution. What had been a local, sun-driven cycle of fertility, in which the legumes fed the corn which fed the livestock which in turn (with their manure) fed the corn, was now broken. Now he could plant corn every year and on as much of his acreage as he chose, since he had no need for the legumes or the animal manure. He could buy fertility in a bag, fertility that had originally been produced a billion years ago halfway around the world.
Liberated from the old biological constraints, the farm could now be managed on industrial principles, as a factory transforming inputs of raw material—chemical fertilizer—into outputs of corn. Since the farm no longer needs to generate and conserve its own fertility by maintaining a diversity of species, synthetic fertilizer opens the way to monoculture, allowing the farmer to bring the factory’s economies of scale and mechanical efficiency to nature. If, as has sometimes been said, the discovery of agriculture represented the first fall of man from the state of nature, then the discovery of synthetic fertility is surely a second precipitous fall. Fixing nitrogen allowed the food chain to turn from the logic of biology and embrace the logic of industry. Instead of eating exclusively from the sun, humanity now began to sip petroleum.
Corn adapted brilliantly to the new industrial regime, consuming prodigious quantities of fossil fuel energy and turning out ever more prodigious quantities of food energy. More than half of all the synthetic nitrogen made today is applied to corn, whose hybrid strains can make better use of it than any other plant. Growing corn, which from a biological perspective had always been a process of capturing sunlight to turn it into food, has in no small measure become a process of converting fossil fuels into food. This shift explains the color of the land: The reason Greene County is no longer green for half the year is because the farmer who can buy synthetic fertility no longer needs cover crops to capture a whole year’s worth of sunlight; he has plugged himself into a new source of energy. When you add together the natural gas in the fertilizer to the fossil fuels it takes to make the pesticides, drive the tractors, and harvest, dry, and transport the corn, you find that every bushel of industrial corn requires the equivalent of between a quarter and a third of a gallon of oil to grow it