Imagine being chained to a treadmill on which you are expected to walk non-stop for the rest of your life.

Among many people, the mere mention of such a thing would conjure up images of Medieval torture.

Yet, in farming terms, there is nothing medieval about it. For more than a century, modern farming in the United States and the rest of the West has been locked into a treadmill — a technological treadmill.

Even so, a team of Alabama Cooperative Extension System economists maintain this is not such a bad thing. While it may seem merciless and unforgiving to some, including many farmers, it is the basis for the modern farming system that has supplied hundreds of millions of consumers across the planet with a food supply that is as diverse as it is affordable.

One of the earliest inklings of this techno-treadmill occurred as South American supplies of guano began running out. Throughout much of the 19th century, guano had served as one of the principal forms of fertilizer for European agriculture.

Matt Ridley explores this all-but-forgotten chapter in agricultural history in The Rational Optimist: How Prosperity Evolves.

In 1898, as fertilizer supplies grew desperately thin, British chemist William Crookes warned that the only way to avoid mass starvation was to develop some way to extract nitrogen from the air.

As Ridley observes, that is what happened roughly 15 years after Crookes’s warning. Inventors Fritz Haber and Carl Bosh developed a way to make large quantities of inorganic nitrogen fertilizer from steam, methane and air.

Other innovations followed: For example, using tractors in place of animals to pull machinery freed up millions of acres of agricultural land to supply human food needs, land that had previously been tied up to feed farm animals.