The Turnip that Saved the World

THE BridgeNews FORUMMay 12, 2000

CHURCHVILLE, Va.-Scientist D. Gale Johnson of the University of Chicago says the population boom started with the spread of alien plant species to Europe during the 18th century. These were potatoes and corn, found in expeditions to the New World, and the turnip, imported to Europe from Asia.

But the real driving force in population growth has been the world's victory over high infant mortality, thanks to clean water, waste treatment and childhood vaccinations.

What's been driving small farmers off their farms? Johnson's history says one of the biggest reasons was the invention of the mechanical reaper by Cyrus McCormick in 1831.

But people's desire to have lots of things besides food in their lifestyles is the force that has driven it since 1950. Johnson, one of the world's most distinguished agricultural economists, recently wrote on the issue in the American Economic Review. He was a member of President Lyndon Johnson's National Advisory commission on food and fiber, where I was a lowly staffer.

Johnson notes the ancient lament quoted above includes nearly all the modern complaints about the effects of excessive population, like deforestation, loss of biodiversity, farming unsuitable land, drainage of the natural refuges for wildlife as well as the massing of people in cities.

Johnson points out that the world surges in population and urbanization really got started in Europe during the 18th century. Between 1750 and 1800, the population of England suddenly rose 50 percent. In the next 50 years, it nearly doubled. Virtually all of the extra people lived in the cities.

Obviously, this meant farms were suddenly producing a great more food per farmer. Otherwise, the city folk would have starved. Johnson says much of the credit goes to the potatoes, corn and turnips that allowed farmers to grow a cattle-feed crop on the half of their land that they previously left fallow.

Leaving the land unplanted so they could hoe the weeds was the farmer's only effective weed control. When growing turnips, they still had to hoe, but at least they got a crop from the whole farm. This meant more people and more cattle could be fed by fewer farmers. The cattle produced more manure, which boosted the yields even more.

According to Johnson, European yields improved 30 percent, from seven bushels of grain harvested for every bushel of seed planted before 1700 to 10 bushels in the period 1750-1820.

For thousands of years, the real bottleneck in human food production was harvesting grain with hand sickles and scythes. Each farmer could harvest only a few acres of ripe grain before the seeds fell out of their husks and were lost on the ground.

McCormick's horse-drawn reaper changed all that. The advance of engineering knowledge started humanity on the path to health, prosperity, and long life for all. But Johnson says the high-yield crops didn't lead to a higher birth rate but simply cut the death rate.

For thousands of years, the average human life span had been 25 to 30 years. Suddenly, about 1650, people began to live longer. By 1800, the average English life span was up to 36 years. Today it's more than twice that.

In the 1800s cities were deathtraps. New York City's infant mortality in 1890 was 264 for every 1,000 births, double the infant death rate in the countryside. Today the United States suffers about eight infant deaths for every 1,000 births.

The same remarkable gains in health and food supply are rapidly spreading to the far corners of the earth, says Johnson. Infant mortality in the poor cities of the world has dropped from more than 300 in 1900 to 157 in 1960 and about 60 today.

India's life expectancy has soared from 23 in 1900 to about 62 today. People in poor countries today get about one-third more calories than their countrymen got at the end of World War II, and their diets contain far more high-quality foods. Meanwhile, the percentage of their spending that goes for food has dropped sharply.

Johnson concludes the whole world is walking rapidly down the path to affluence pioneered by the First World. The secret? Knowledge, Johnson says.

If you don't like lots of affluent people raising healthy kids and working to save the environment, blame colleges and research laboratories. Come to think of it that's just what today's World Bank and World Trade Organization protesters are doing.