The Midwestern United States was, until relatively recently, sitting on top of some of the deepest topsoil on earth.
Ten thousand years of prairie. Bison, fire, deep-rooted grasses, the slow accumulation of organic matter into a layer of black soil sometimes two feet thick. Soil that farmers in other parts of the world would have wept at the sight of.
Then the plough arrived.
In 2021, a team from the University of Massachusetts used satellite imagery and LiDAR to measure what was left. Their finding: roughly a third of the Corn Belt, around 30 million acres, has completely lost its A-horizon. The carbon-rich topsoil is simply gone. Scraped off the hilltops by a hundred and fifty years of tilling and rain, washed downslope, into rivers, into the Gulf.
The USDA had previously estimated that none of those same fields had lost their topsoil.
None.
The satellites disagreed.
Every year, the United States loses around five tons of soil per acre. Ten times the rate at which it forms. A layer as thick as a dime, peeled off every twelve months, across tens of millions of acres, and sent downhill.
The crops being grown on this land, the corn and soy that replaced the prairie, are in large part used for ethanol, high fructose corn syrup, and livestock feed. The livestock feed portion is the only one that gets criticised in polite company.
The prairie took ten thousand years to build.
We scraped a third of it off in under two hundred.
The people currently telling us to grow more crops instead of raising cattle are, presumably, unaware that the crops are already eating the ground they stand on.