Dust Bowl Wind Storm
American soil scientist W.C. Lowdermilk studied other countries and ancient civilizations to learn how best to prevent more soil erosion disasters like the Dust Bowl of the 1930s.
Photograph by the World History Archive
That question headlining a 1984 National Geographic article on soils remains as relevant today as it was more than 30 years ago.
We lavish attention on our food, we want to know where it came from, who grew it, and whether it is “conventional” or “organic.” But we give hardly a passing thought to the ground our food grew in.
Soil could use some more attention and respect. After all, soil is the thin skin of our Earth where we plant and grow the vital grain crops like wheat, rice, and corn that feed more than seven billion of us.
And while the future rests on the soil beneath our feet, as National Geographic also put it in a 2008 article on soils, history is littered with the remains of civilizations that ignored, exploited, and degraded the soil beneath their feet.
One-third of the world’s soil already has been damaged by water and wind erosion, deforestation, compaction, nutrient depletion, and pollution. By our own actions, we are losing soil faster than nature can create it, and as population keeps growing we also pave over some of the most productive farmland for urban areas. The United Nations says that unless we protect the remaining soil and improve land use and conservation practices, the global amount of arable and productive land per person in 2050 will be only a quarter of what it was in 1960.
In the late 1930s, American soil scientist W.C. Lowdermilk traveled across Europe, North Africa, and the Middle East to investigate why past civilizations failed, or persevered, by looking at the effect of agricultural practices over the past 7,000 years. He visited lands that had been in cultivation for centuries to understand the link between soil erosion and the fate of civilizations.
Lowdermilk sought insights that could help avoid a repeat of the Dust Bowl, which was a soil erosion disaster that hit the southern Great Plains of the United States in the 1930s. It was caused by the “Great Plow-Up” of perennial grasslands to grow annual wheat that coincided with a decade-long drought. Huge dust storms blew Plains soil as far east as Washington, D.C., and thousands of people in Oklahoma, Kansas, and nearby states were driven from their land.
On Lowdermilk’s 18-month journey of toppled empires and vanished civilizations, he found that soil losses from wind and water erosion, soil salination from irrigation, deforestation, overgrazing, and conflicts between crop farmers and herdsmen all had contributed to societal failures. He also found that careful stewardship of soil with land terracing, crop rotation, tree planting and other methods that keep soil covered has allowed societies to flourish for centuries.
A 2015 study in Science called “Soil and Human Security in the 21st Century” reports that a recent rise in research on soils and soil health has been encouraging, but that soil conservation—preserving soil carbon, cutting erosion, and improving soil nutrients—must increase significantly, and soon, to protect the remaining soils we rely on.
“These are challenging goals that will be difficult to achieve,” the study says, “much like the approaches required to contend with climate change.”
Unless we ramp up our efforts to conserve remaining soils, our own future is at risk, just like the vanished civilizations Lowdermilk studied more than 75 years ago. In decades ahead the pressure on the world’s soils to to grow even more food will only rise as population likely rises past nine billion by 2050.
While we observe World Food Day in October, remember that healthy soils are vital to the success of all farmers.
Education campaigns about soils are increasing. The U.N. declared 2015 the International Year of Soils, and World Soils Day was December 4 that year.
It's about time. Here's to soil.
Dennis Dimick grew up on a farm in Oregon and studied agriculture in college. He serves as National Geographic’s Executive Editor for the Environment. You can follow him on Twitter, Instagram, and flickr.
complex way of life that developed as humans began to develop urban settlements.
(geology) the concentration of sediments from the weight of overlying earth.
destruction or removal of forests and their undergrowth.
process of emptying a supply or substance.
(1930-1940) term for the Great Plains of the U.S. and Canada when severe dust storms forced thousands of people off their farms.
weather pattern of wind blowing dust over large regions of land.
act in which earth is worn away, often by water, wind, or ice.
introduction of harmful materials into the environment.
top layer of the Earth's surface where plants can grow.