[Note: The following is a significant expansion of the Soil Destruction section of Sample 44.]
Spencer Wells lamented the transition to food production, when folks shifted from foraging to farming and herding. “Instead of being along for the ride, we climbed into the driver’s seat.” Richard Manning agreed. He said that in the good old days, “we didn’t grow food; food grew.” Food production took an increasing toll on the soil. Folks didn’t fully understand the consequences of what they were doing.
In the good old days, wild ecosystems were complex communities of plants and animals. These wild communities coevolved over time, which kept them fine-tuned for long term survival in ever changing local conditions. Believe it or not, they could thrive, century after century, without irrigation systems, synthetic fertilizer, pesticides, fossil powered machinery, human stewards, and so on.
With the transition to plant and animal domestication, humans could produce greater quantities of food, and feed more mouths. But the artificial ecosystems they created (cropland and pasture) commonly reduced natural biodiversity, encouraged erosion, and depleted soil fertility.
Walter Youngquist wrote that the average depth of the world’s topsoil is less than 12 inches (30 cm). He added that almost all modern folks consider oil to be a vital strategic resource. Oddly, far fewer have a profound appreciation for soil, the most precious mineral treasure of all. For almost the entire human saga, our ancestors left fossil hydrocarbons in the ground, where they belong. Soil is vital for the survival of the entire family of life — yesterday, today, and forever after.
He warned that, from a human timeframe, topsoil is a nonrenewable resource, because new topsoil is created over the passage of centuries, on a geological timeframe. “Overall, one-third of the topsoil on U.S. cropland has been lost over the past 200 years.” Humans are destroying it far faster than nature creates it.
Youngquist mentioned the work of Peter Salonius, a soil scientist who performed 44 years of research. Salonius came to the conclusion that all extractive agriculture, from ancient times to the present, is unsustainable. Environmental history clearly supports his conclusion.
Writing in 2000, J. R. McNeill wrote that the U.S. was currently losing 1.7 billion tons of topsoil per year to erosion. At that time, there were 281 million Americans. So, the loss would have been six tons per person. Writing in 2007, David Montgomery noted that each year, the world was losing 24 billion tons of soil. In 2015, Joel Bourne reported that every year, a million hectares (2.4 million acres) of world cropland are taken out of production because of erosion, desertification, or development.
Richard Manning wrote, “There is no such thing as sustainable agriculture. It does not exist.” David Montgomery agreed. “Continued for generations, till-based agriculture will strip soil right off the land as it did in ancient Europe and the Middle East. With current agricultural technology though, we can do it a lot faster.”
Dale and Carter wrote a history of humankind’s war on soil. Immigrants who colonized the U.S. behaved much like civilized colonists throughout history. “They caused more waste and ruin in a shorter time than any people before them because they had more land to exploit and better equipment with which to exploit it. Some ruined their land because they knew no better, and others destroyed out of greed for immediate profits, but most of them did it because it seemed the easiest thing to do.”
David Montgomery described the farmers of early America. Tobacco was a goldmine, because it reaped six times more income than any other crop, and it could be shipped across the Atlantic and arrive in perfect condition.
Growing tobacco was labor intensive, and slaves provided the muscle power. It was also a heavy feeder on soil nutrients. A farmer could make great money for three or four crops, after which the soil was severely depleted.
At that point, they often abandoned the useless fields, and cleared forest to create new ones, for another round of jackpot moneymaking. It was easier and more profitable. In the early days, frontier land was abundant and cost little or nothing.
Back in Europe, it was foolish to greedily treat topsoil like a rape and run disposable resource. Over time, agriculture had eventually collided with serious limits, when it was no longer easy to expand cropland area by exterminating forests. So, respectful consideration was given to future generations of descendants, who wouldn’t enjoy inheriting a (%@&#!) wasteland. Each generation deliberately made efforts to slow soil deterioration by regularly adding manure, compost, leaves, crushed bone, and other fertilizers. Soil was treated like gold.
On the other hand, in early America, ambitious high achievers thought that being conservative stewards of the land was ridiculously stupid. Livestock was needed to produce manure, and livestock required pasture. Tobacco acres earned big money fast, and pasture acres did not. Profit was their god word.
Clive Ponting noted that a bit after the tobacco boom, the cotton gin made it more profitable to manufacture cotton fabric, rather than wool. Cotton became a new goldmine for farmers and slave traders. In Africa, slaves were often purchased by trading cotton cloth for them. Like tobacco, cotton was very hard on the soil. Compared to a food crop, it extracted 11 times the nitrogen, and 36 times the phosphorus. Between 1815 and 1860, cotton was 50 percent of U.S. exports.
As with tobacco, depleted cotton fields were abandoned, and farm country migrated westward, as it devoured ancient forests. It was cheaper, easier, and more profitable to move on, so they did. David Montgomery described how these folks broke every cardinal rule of careful land stewardship. Farmers did continuous planting without crop rotation, used little or no manure, and plowed straight up and down hills (not contour plowing).
Highly explosive ignorance resulted in painful lessons and enduring destruction. Stripping away the forests in hill country deleted what had held the soil in place for thousands of years. Damage was extreme in the Piedmont belt of the southeastern U.S. Further north, the wreckage was a bit lighter, because snow protected the soil during winter months. But in the south, heavy rains were common. Some regions eventually lost most of their soil, exposing portions of bedrock.
Shockingly huge gullies were created in the wake of deforestation. In Alabama, gullies up to 80 feet (24 m) deep soon followed land clearance. One erosion gully near Macon, Georgia was 50 feet deep (15 m), 200 feet across (61 m), and 300 yards long (274 m). Montgomery wrote, “By the early 1900s, more than five million acres of formerly cultivated land in the South lay idle because of the detrimental effects of soil erosion.”
As the colonization of the U.S. proceeded, folks continued migrating westward, moving beyond forested regions to the open prairies. They perceived prairies to be wastelands, because they were largely treeless. Many pushed onward toward Oregon, hoping to settle in lands having fertile soil. In the process, they skipped right past the tallgrass prairie, home to the nation’s most fertile soil by far. Eventually, they realized their mistake, and the primo tallgrass belt was settled.
Latecomers got the less desirable shortgrass prairie, which had highly fertile soil, but it was lighter in texture, and more vulnerable to erosion. In shortgrass country, strong winds and periodic droughts were normal and common, but evolution had fine-tuned the wild ecosystem to survive these conditions.
The natural vegetation was drought tolerant, retained moisture, and kept the soil from blowing away. Unfortunately, the settlers brought state of the art steel plows, and proceeded to strip the vegetation off the land, and expose the precious soil. Unintentional foolishness led to catastrophe.
David Montgomery mentioned a 1902 report by the U.S. Geological Survey that classified the high plains as being suitable for grazing, but not farming. It was “hopelessly nonagricultural” because it was ridiculously prone to erosion. Gullible farmers were encouraged by sleazy speculators to settle on the land and get rich quick. And many did, for a while.
Walter Lowdermilk wrote that much of the time between 1900 and 1930 was a highly unusual period of above average precipitation. During the wet years, farmers enjoyed big harvests and generous profits. Wheat could do well in the shortgrass climate, and a thriving wheat field protected the fragile soil from erosion. But in drought years, the wheat withered, and there was nothing to hold the soil in place when the winds began howling.
Tractors were the latest cool gizmo. A lad with a tractor could farm 15 times more land than a lad who used draft animals. Cropland area greatly expanded, exposing more and more soil, which the winds carried away. The stage was set for the Dust Bowl.
Marc Reisner wrote, “The first of the storms blew through South Dakota on November 11, 1933. By nightfall, some farms had lost nearly all of their topsoil. At ten o’ clock the next morning, the sky was still pitch black. People were vomiting dirt.”
“If not the worst man-made disaster in history, it was, at least, the quickest.” From 1934 to 1938, there were numerous huge dust storms, “black blizzards” that could turn day into night. In 1934, congressmen in Washington D.C. went outside to watch the sky darken at noon. The jet stream carried dust across the ocean to Europe.
In many regions, more than 75 percent of the topsoil was blown away by the end of the 1930s. The Department of Agriculture estimated that 50 million acres of farmland had been ruined and abandoned during the Dust Bowl.
Humankind’s war on soil continues, and we’re winning. In a 2012 article in Time magazine, John Crawford, a risk analysis expert, wrote that “A rough calculation of current rates of soil degradation suggests we have about 60 years of topsoil left. Some 40% of soil used for agriculture around the world is classed as either degraded or seriously degraded — the latter means that 70% of the topsoil, the layer allowing plants to grow, is gone.” [LOOK]
In some locations, visible evidence of this loss is obvious, in large clouds of dust, ghastly erosion gullies, or rain shower runoff that looks like chocolate milk. In other places, the loss may not be readily visible during a lifetime. When you gaze at a large field, decade after decade, you might not notice the gradual loss of tons of soil.
Walter Youngquist mentioned a study finding that when one hectare of land lost six metric tons of soil, the surface of the soil dropped just one millimeter. He thought that erosion was similar to cancer, a persistent intensifying destroyer.
Soils with less humus absorb less water, which increases runoff and soil loss. Light soils are more likely to disappear than dense soils. Sloped land is most prone to erosion. Some regions of Europe typically receive gentle rain showers, while some locations in the U.S. often receive heavy cloudbursts. Of course, wild grasslands and forests excel at absorbing moisture, building humus, and retaining soil.
When forest is cleared, or grassland is plowed, the soil is exposed to incoming sunlight. As the soil warms up, microbial activity is stimulated, which accelerates the oxidation of the carbon-rich humus. Precious carbon built up over the passage of years is dispersed into the atmosphere as carbon dioxide. Soil fertility declines, and will not be promptly restored, if ever.
All tilling, to varying degrees, degrades or destroys soil. The healthy green blanket of natural vegetation that protects the precious topsoil is entirely torn off the face of the land. The soil dries out, hardens, and absorbs less precipitation, which accelerates runoff. This increases the chances of sheet erosion, gullying, landslides, and flooding. It can sometimes take centuries for nature to replace the unprotected topsoil lost in a stormy hour.
Long ago, the Mediterranean basin became a hotbed of civilizations as agriculture spread westward out of Mesopotamia. The Mediterranean climate provided heavy winter rains, making it a suitable place to grow wheat and barley. Much of the basin was sloped land, which was extensively deforested over time, driven by growing demand for lumber and firewood.
Flocks of sheep and goats roaming on the clear-cut hillsides overgrazed, encouraged erosion, and prevented forest recovery. By and by, the rains leached out the nutrients, and washed much of the fertile soil off the hillsides. In many locations, bare bedrock now basks in the warm sunshine, where ancient forests once thrived in ancient soils.
Carter and Dale noted that, in the good old days, the Mediterranean used to be among the most prosperous and progressive regions in the world. But when they wrote in 1955, most of the formerly successful civilizations had become backward, or extinct. Many had just a half or a third of their former populations. Most of their citizens had a low standard of living, compared to affluent societies.
Montgomery noted that these ancient civilizations often enjoyed a few centuries of prosperity, as they nuked their ecosystems. Sadly, the soils of the Mediterranean basin were heavily damaged by 2,000 years ago, and they remain wrecked today. They are quite likely to remain wrecked for many, many thousands of years. Much of the region that once fed millions is a desert today.
I never learned any of this in school. Instead, this region was celebrated as the glorious birthplace of civilization, democracy, culture, and science. It had incredible architecture and dazzling artwork. It was home to brilliant writers and philosophers (no mention of slaves). Many of our public buildings today, with their ornate marble columns, pay homage to this era when we first got really good at living way too hard.
Of course, progress never sleeps. In 2000, J. R. McNeill published a fascinating (and sobering) book on the environmental history of the twentieth century, when cultures blind drunk on gushers of cheap oil spurred a population explosion that probably caused the most destruction to Earth since the Chicxulub asteroid wiped out the dinosaurs.
In a 2014 book, McNeill narrowed his focus to the catastrophic changes that have occurred since 1945. He noted that in the world, about 430 million hectares (seven times the size of Texas) has been irreversibly destroyed by accelerated erosion. “Between 1945 and 1975, farmland area equivalent to Nebraska or the United Kingdom was paved over.” By 1978, erosion had caused the abandonment of 31 percent of all arable land in China.