A moldboard plow. Image: Library of Congress
This week, NASA has been publishing satellite photos of Kansas's tallgrass prairie fires. They're pretty striking; across the western part of the state, the smoke from dozens of controlled burns wafts into the sky. Tallgrass prairie can grow nine feet high, and constitutes a complex ecosystem that quickly becomes fire-prone in the dry season.
Those fires used to dot the 170 million acres of tallgrass that once spread between the US and Canada. Native Americans used to set them to help keep the land fertile and the blazes predictable, beginning thousands of years ago. Now, according to NASA, only 4 percent of that prairie remains. Some estimates put the figure even lower.
Smoke and burn scars from wildfires in Kansas. Image: Jeff Schmaltz/NASA
The fascinating—and jarring—thing about the tallgrass prairie's near-extinction is that almost all of it vanished in a single human lifetime, thanks to a single technology: The moldboard plow.
"After thriving over 8,000 years aided by the restorative effects of drought, bison grazing, lightning fires and deliberate burns set by the Native Americans, this diverse natural community was reduced to 2% of its original size by the early 1900s," Canadian researcher Pam Graham writes, citing the US National Park Service statistics. "It took the steel mold-board plow just half a century to bring the tall grass prairie to the brink of destruction."
Here's a quick explanation of how the moldboard plow works, from Wikipedia:
[The moldboard plow] not only cuts furrows with a share (cutting blade) but turns the soil. A coulter (or skeith) could be added to cut vertically into the ground just ahead of the share (in front of the frog), a wedge-shaped cutting edge at the bottom front of the mouldboard with the landside of the frame supporting the undershare (below-ground component) ...
The mouldboard plough greatly reduced the amount of time needed to prepare a field, and as a consequence, allowed a farmer to work a larger area of land. In addition, the resulting pattern of low (under the mouldboard) and high (beside it) ridges in the soil forms water channels, allowing the soil to drain. In areas where snow buildup is an issue, this lets farmers plant the soil earlier, as the snow runoff drains away more quickly.
Once John Deere introduced the first steel plow in 1837, it only took a few years to catch on. It made farming more efficient, and more profitable. Newly built railroads made commodities easier to transport, and the plow made it easier to harvest them. An estimated 98 percent of the prairie subsequently vanished between 1830 and 1900, having been converted for agricultural uses.
There's a lesson of two about the vast power of human technology here, and we're not even talking about tech from this century or even the last. Once the efficiency of the plow was made clear, the plow spread from farm to farmer, who adopted it, fresh out of beta. Without an understanding of the ecological consequences—much less environmental regulations—the new technology enabled us to toally transform—and largely obliterate—a sprawling, thriving ecosystem in just a couple generations.
In the age of climate change, deforestation, and mass species loss, there are still many who doubt the capacity of humans to permanently alter our environment. I'd remind them of what we were able to pull off with just a plow.