Remembering the Dust Bowl on World Soil Day
December 5th is World Soil Day. Wasn’t on your calendar? Didn’t get a Hallmark card for the occasion?
Here’s the dirt on why soil matters.
Healthy societies need healthy soil. Healthy soil produces healthy food. Healthy soil also sequesters carbon dioxide, helping to stabilize the earth’s climate.
Healthy soil is alive. The U.N. Food and Agriculture Organization tells us that “there are more living organisms in a tablespoon of soil than there are people on health.” That’s over 7 billion! Yet every year, 50,000 square kilometers of soil, an area the size of Costa Rica, is lost. A third of the world’s soils are degraded.
When soil erodes faster than new soil is created, civilizations decline. Reminders abound in archaeological ruins, yet hubris clouds us from fully realizing our dependence on the health of the earth beneath our feet.
We don’t need to look far back in U.S. history to see how vulnerable soils can be.
In the early decades of the twentieth century, railroad brochures and government incentives lured suitcase farmers to the semi-arid Great Plains, with promises that “rain follows the plow.” The settlers embraced newly available tractors, powerful plows, and mechanized harvesters to turn over the sod that had long sustained Native American tribes and millions of bison.
The heavy plowing began during years of rain, and early harvests were good. High wheat prices, buoyed by demand and government guarantees during the First World War, encouraged ever more land to be turned over. But then the Great Depression hit. The price of wheat collapsed and fields were abandoned. When the drought arrived in the early 1930s, the soil blew. Stripped of its living carpet, freed from the intricate matrix of perennial prairie grass roots, the earth took flight in relentless winds.
Clouds as tall as mountains and black as night rolled over the land. Regular dust storms pummeled the homesteaders. The big ones drew the notice of city slickers when they clouded the sun in New York City and Washington, D.C., even sullying ships hundreds of miles out in the Atlantic. Sand dunes formed and spread, burying railroad tracks, fences, and cars. Children and the elderly died from “dust pneumonia.” People fled the land in droves.
The sodbusters had quickly illuminated the folly of the 1909 Bureau of Soils proclamation: “The soil is the one indestructible, immutable asset that the nation possesses. It is the one resource that cannot be exhausted; that cannot be used up.” The Great Plains looked like it would revert back to its moniker from earlier U.S. maps: the Great American Desert.
The Dust Bowl ultimately covered 100 million acres in western Kansas, the Oklahoma and Texas Panhandles, northeastern New Mexico, and southeastern Colorado.
It wasn’t until the spring of 1935, when a series of dust storms reached far-flung Washington, D.C., that a reluctant Congress finally allocated resources to help stabilize the soil. A new agency, the Soil Conservation Service, helped to introduce land care practices to help hold down the earth. Grasses were reintroduced. Trees were planted in shelter belts to slow the persistent winds. With contour farming and terracing, farmers could follow the natural shape of the land rather than plowing straight down hills and valleys. Crop rotations and strip cropping — farming in narrow rows alternating with fallowed land — allowed some protective cover to remain on the soil.
Some of the Dust Bowl land never recovered. Settled communities became ghost towns. But with improved land stewardship, many of the once-affected areas became major food producers. Between 1931 and 1933 wheat production in Kansas, Texas, Oklahoma, and Colorado was slashed by nearly three-quarters from a high of 411 million bushels. Soil recovery took until 1947 for wheat levels reach that level again.
After World War II, well-drilling and pumping technologies allowed farmers to tap into the Ogallala aquifer, a vast reservoir of water beneath the Plains, stretching from southern South Dakota through the Texas Panhandle. Irrigation expanded, with center-pivot sprinklers creating the green circles overlain on brown squares that are familiar to anyone who has flown over the central United States. By 2016, the combined wheat output of Kansas, Texas, Oklahoma, and Colorado was close to 800 million bushels, a third of the U.S. wheat harvest.
In recent decades irrigation has allowed the traditional Corn Belt to move westward onto drier lands. Kansas, for instance, sometimes called “the Wheat State,” harvesting one-sixth of the U.S. crop, now produces as much corn as it does wheat. The wheat is primarily rainfed, but more than half the corn is irrigated.
As extraction of the underground water has increased, however, water tables have fallen. The depletion is particularly concerning in the Central and Southern Plains where there is virtually no replenishment of the aquifer from rainfall. The underground water there is like oil in a well — once the well is pumped dry, the resource is gone. A number of farming communities in the former Dust Bowl states are reaching “peak water.” When irrigation wells run dry, some farmers return to lower-yielding rainfed farming; others abandon wheat all together.
In Kansas the average drop in the water table is 23 feet (7 meters), but drops of 150 feet or more have been reported. The fall in water tables is even greater in the Texas Panhandle. Statewide, Texas’ irrigated area is down more than 20 percent from its high nearly 40 years ago. Only recently, after back-to-back droughts, were limits placed on withdrawals from individual wells to slow the depletion. According to scientists at the University of Texas at Austin and the U.S. Geological Survey, if current rates of extraction continue, irrigation over a third of the southern High Plains will be untenable within 30 years.
Beyond the farm, climatologists are making it clear that droughts will come more frequently as the planet heats up. So rainfed crops are in trouble, too. Models agree that with the global warming in store absent dramatic cuts in greenhouse gas emissions, much of the western United States — from Kansas to California — could enter into a long-term state of dryness, what physicist Joseph Romm has termed “dust-bowlification.”
With soil conservation measures in place, when drought revisited the Plains, isolated dust storms cropped up, but a full-blown Dust Bowl did not develop. But as rainfall patterns change and underground resources are overused, can the soils hold?
In geological time, the U.S. bread basket experiment is relatively short.
While our understanding of and respect for the soil is greater now than it was at the turn of the last century, erosion still exceeds new soil formation on too many acres. Climate change and the pressures of population growth and rising consumption that are pushing farmers to produce ever more food on limited land will make it harder to avoid a repeat of history.
Janet Larsen is the founder of One Planet Strategies LLC and co-author of The Great Transition: Shifting from Fossil Fuels to Solar and Wind Energy.
To learn more about the U.S. Dust Bowl, I recommend Timothy Egan’s book, The Worst Hard Time: The Untold Story of Those Who Survived the Great Dust Bowl (New York: Mariner Books, Houghton Mifflin Company, 2006) and Ken Burns’ film The Dust Bowl. I also wrote about dust bowls in other parts of the world at Earth Policy Institute here.
This piece is adapted from an Earth Policy Institute Plan B Update.