The History of Agriculture

My book on the grain merchants has reverted to the title I first thought of, “Alphabet Soup—The Seven Companies at the Centre of Your Food Supply.” I am still aiming for publication in early-November.

There is a saying in the book business that “the wastepaper basket is a writer’s best friend.” In putting together the first draft of my book, I deleted large chunks of what I had previously written. I have fished out some of the least bad bits, and I will share them with you over the coming weeks. This is the first:

As Richard Manning wrote in “Against the Grain: How Agriculture has Hijacked Humanity,” of the roughly 300,000 years that mankind has wandered this earth, we have spent 290,000 of those as hunter-gatherers. Agriculture is a relatively new game for us and, as you have realised when visiting your local supermarket, we still have hunter-gatherer genes.

And even during the last 10,000 years, farming has changed little. Fields were regularly left fallow, and animal manure was the sole fertiliser. It was only in the early 1800s that scientists began to understand that inorganic minerals such as nitrogen, potassium, lime, and phosphoric acid could replenish depleted soils, leading to the production of mineral fertilizers.

The search for fertiliser led merchants and scientists to the dry seabird islands off the South American and South African coasts, where immense deposits of bird droppings, rich in nitrogen and phosphorus, had accumulated over centuries. Guano mining became a profitable business. Between 1840 and 1880, guano nitrogen made a vast difference to European agriculture, but the best deposits were soon exhausted. Rich mineral nitrate deposits were found in Chile, and nitrate mines gradually took the place of guano in the late 19th century.

However, as Michael Pollen writes in The Omnivore’s Dilemma, the great turning point in the modern history of agriculture can be dated to the day in 1947 when a huge munitions plant at Muscle Shoals, Alabama, switched over from making explosives to making chemical fertilizer. He explains that at the end of World War II, the US government found itself with a surplus of ammonium nitrate, the principal ingredient in making explosives. Ammonium nitrate is an excellent source of nitrogen for plants, and the chemical fertilizer industry (along with that of pesticides, which are based on the poison gases which were also developed for war) was the product of the government’s effort to convert its war machine to peacetime purposes.

Even though the earth’s atmosphere is about 80 percent nitrogen, nitrogen atoms have to be split and joined to hydrogen atoms (“fixed”) before they can be used for fertilizer or bombs. A German Jewish chemist named Fritz Haber worked out how to do that in 1909. Before he made that discovery, all the usable nitrogen on earth had to be fixed by soil bacteria or by electrical lightning, which breaks down nitrogen bonds in the atmosphere.

In his book, Enriching the Earth: Fritz Haber, Carl Bosch and the Transformation of World Food Production, Vaclav Smil explains that “there is no way to grow crops and human bodies without nitrogen.” Without Haber’s invention, the amount of life on earth would have been limited by the small amount of nitrogen that bacteria and lightning alone could release. Mr Smil argues that as a result, the Haber-Bosch process for fixing nitrogen (Bosch commercialised Haber’s idea) was the most important invention of the 20th century. He estimates that 40 percent of the people on the earth today would not be alive if not for the invention. Without synthetic fertilizer, billions of people would never have been born.

Although Fritz Haber won the Nobel Prize in 1918 for “improving the standards of agriculture and the well-being of mankind,” he has since largely been airbrushed out of history. During World War I he helped the German war effort by making bombs from synthetic nitrate. Worse, he also developed poison gases including Zyklon B, the gas used in the Nazi concentration camps.

Michael Pollen argues that once mankind had 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. The Haber-Bosch process works by combining nitrogen and hydrogen gases under immense heat and pressure, the energy supplied by electricity. The hydrogen is supplied by oil, coal or, most commonly today, natural gas.

Growing crops, which from a biological perspective had always been a process of converting sunlight into food, has become a process of converting fossil fuels into food. More than half of the world’s supply of usable nitrogen is now man-made—and more than half of all the synthetic nitrogen made today is applied to corn alone.

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