The effects of soil erosion extend beyond the loss of fertile land, and this fact should ring alarm bells for American scientists, as soil erosion in the Midwest of the United States is up to a thousand times greater than before the rise of modern agriculture.
According to recent research from the University of Massachusetts, the rate of soil erosion in the Midwest is 10 to 1,000 times greater than pre-agricultural erosion rates. These newly discovered pre-agricultural rates, which reflect the rate at which soils form, are orders of magnitude lower than the US Department of Agriculture's upper allowable limit of erosion (USDA).
The research, published in the journal Geology, makes use of a rare element called beryllium-10, which is produced when stars in the Milky Way explode and send high-energy particles known as cosmic rays hurtling toward Earth.
When galactic shrapnel collides with the Earth's crust, it splits the oxygen in the soil apart, leaving tiny trace amounts of beryllium-10 that can be used to precisely calculate average erosion rates over thousands to millions of years.
"For the first time, we know what the natural rates of erosion are in the Midwest," says geologist Caroline Quarrier, who completed the research as part of her master's thesis at the University of Massachusetts (UMass) Amherst.
"And because we now know the rate of erosion before Euro-American settlement, we can see exactly how much modern agriculture has accelerated the process."
