40% of their study area used no till farming.
Researchers asked what if it was 100%? Results were astounding.
It would take 10,000 years to reach the levels of soil loss that will
unfold in just a century under business as usual.
In 2021, a team of researchers from the University of Massachusetts
Amherst estimated that croplands in the US Midwest were losing
topsoil at a frightening rate—fast enough that it’s been eradicated
completely from over one-third of the US Corn Belt.
They’ve now taken their earlier work a step further, demonstrating
that an already commonplace agricultural practice could bring this
destruction to a standstill—or even reverse it.
They plugged their original numbers into a model that simulated
regional soil degradation decades into the future, showing what would
happen if current rates of soil loss remained unchanged—or
alternatively, if we did something about it.
They didn’t imagine a whole new technology, but rather focused on a
methodology that is shovel-ready. No-till farming methods are already
practiced across 40% of the farming area the researchers focused on,
and so they simulated what would happen if we expanded a softer
version of these measures over a larger area of land.
This revealed that on the one hand, if we stick with conventional
farming methods and unbridled tilling goes on, it will whittle away at
the topsoil and drive losses of 8.8 billion metric tons over the next
100 years. That would also release 170 million metric tons of organic
carbon that’s currently locked into this crucial surface layer.
However, this dire picture could be almost entirely reversed, if
farmers adopt low-intensity till practices across the studied area.
Unlike no-till methods, this alternative would still allow this
practice but at a reduced rate, and may also involve incorporating
crop residue onto the surface to further buffer soil from erosion.
The researchers’ model showed that
expanding such practices across the entire midwestern region could
reduce projected soil losses by 95% over the next 100 years. The pace
of loss would be so significantly slowed down by these measures, in
fact, that it would take 10,000
years to reach the levels of
soil loss that will unfold in just a century, if regional farming
methods don’t change at all. The fact that all this can be achieved
with a watered down version of the no-till that is already practiced
across parts of this region, is an encouraging sign.
In conversations about sustainable agriculture that often focus on
important issues like making crops more adaptable, reducing fertilizer
and pesticides, and increasing yields, soil health often gets
overlooked. Yet this is where all the agricultural action happens,
especially in the rich surface layer where crops take root and are
nourished, and which is also especially vulnerable to erosion.
This oversight is already costing
crops: soil degradation in the Midwest has so far reduced yields by
6%, costing an estimated $2.8 billion, the researchers explain in
their study. And since degradation happens much faster when there’s
more soil to degrade, now would be the optimal time to intervene to
stop this economic and agricultural loss, they say.
“There’s real incentive to
act now when we’ll see the most long-term benefit.”
